SELECT 
  PFD.range_input 
FROM 
  cscart_product_filters AS PF 
  LEFT JOIN cscart_product_filter_descriptions AS PFD ON PF.filter_id = PFD.filter_id 
WHERE 
  PF.feature_id = '737'

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "0.70"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "PF",
          "access_type": "ref",
          "possible_keys": [
            "feature_id"
          ],
          "key": "feature_id",
          "used_key_parts": [
            "feature_id"
          ],
          "key_length": "3",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "0.35",
            "data_read_per_join": "72"
          },
          "used_columns": [
            "filter_id",
            "feature_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "PFD",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "filter_id"
          ],
          "key_length": "3",
          "ref": [
            "dev2.PF.filter_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "0.70",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "filter_id",
            "range_input"
          ]
        }
      }
    ]
  }
}