SELECT 
  cscart_product_filters.feature_id, 
  cscart_product_filters.filter_id, 
  cscart_product_filters.field_type, 
  cscart_product_filters.round_to, 
  cscart_product_filters.display, 
  cscart_product_filters.display_count, 
  cscart_product_filter_descriptions.filter, 
  cscart_product_features.feature_type, 
  cscart_product_features.filter_style, 
  cscart_product_features_descriptions.prefix, 
  cscart_product_features_descriptions.suffix 
FROM 
  cscart_product_filters 
  LEFT JOIN cscart_product_filter_descriptions ON cscart_product_filter_descriptions.filter_id = cscart_product_filters.filter_id 
  AND cscart_product_filter_descriptions.lang_code = 'ru' 
  LEFT JOIN cscart_product_features ON cscart_product_features.feature_id = cscart_product_filters.feature_id 
  LEFT JOIN cscart_product_features_descriptions ON cscart_product_features_descriptions.feature_id = cscart_product_filters.feature_id 
  AND cscart_product_features_descriptions.lang_code = 'ru' 
WHERE 
  cscart_product_filters.status = 'A' 
  AND (
    cscart_product_filters.categories_path = '' 
    OR FIND_IN_SET(
      921, cscart_product_filters.categories_path
    )
  ) 
ORDER BY 
  cscart_product_filters.position, 
  cscart_product_filter_descriptions.filter

Query time 0.00069

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.29"
    },
    "ordering_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_product_filters",
            "access_type": "ALL",
            "rows_examined_per_scan": 88,
            "rows_produced_per_join": 8,
            "filtered": "10.00",
            "cost_info": {
              "read_cost": "8.17",
              "eval_cost": "0.88",
              "prefix_cost": "9.05",
              "data_read_per_join": "633"
            },
            "used_columns": [
              "filter_id",
              "categories_path",
              "feature_id",
              "position",
              "field_type",
              "status",
              "round_to",
              "display_count",
              "display"
            ],
            "attached_condition": "((`dev2`.`cscart_product_filters`.`status` = 'A') and ((`dev2`.`cscart_product_filters`.`categories_path` = '') or (0 <> find_in_set(921,`dev2`.`cscart_product_filters`.`categories_path`))))"
          }
        },
        {
          "table": {
            "table_name": "cscart_product_filter_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "filter_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "dev2.cscart_product_filters.filter_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 8,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.20",
              "eval_cost": "0.88",
              "prefix_cost": "12.13",
              "data_read_per_join": "9K"
            },
            "used_columns": [
              "filter_id",
              "lang_code",
              "filter"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_features",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "feature_id"
            ],
            "key_length": "3",
            "ref": [
              "dev2.cscart_product_filters.feature_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 8,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.20",
              "eval_cost": "0.88",
              "prefix_cost": "15.21",
              "data_read_per_join": "13K"
            },
            "used_columns": [
              "feature_id",
              "filter_style",
              "feature_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_product_features_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "feature_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "dev2.cscart_product_filters.feature_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 8,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.20",
              "eval_cost": "0.88",
              "prefix_cost": "18.29",
              "data_read_per_join": "24K"
            },
            "used_columns": [
              "feature_id",
              "prefix",
              "suffix",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}