SELECT 
  DISTINCT `B`.`brand_id`, 
  `B`.`brand` 
FROM 
  `cscart_products` AS `P` 
  JOIN `cscart_brands` AS `B` ON `P`.`brand_id` = `B`.`brand_id` 
WHERE 
  `P`.`company_id` = 692

Query time 0.01002

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2452.44"
    },
    "duplicates_removal": {
      "using_temporary_table": true,
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "P",
            "access_type": "ALL",
            "possible_keys": [
              "cscart_products_brand_id_index"
            ],
            "rows_examined_per_scan": 17394,
            "rows_produced_per_join": 1739,
            "filtered": "10.00",
            "cost_info": {
              "read_cost": "1669.71",
              "eval_cost": "173.94",
              "prefix_cost": "1843.65",
              "data_read_per_join": "12M"
            },
            "used_columns": [
              "product_id",
              "company_id",
              "brand_id"
            ],
            "attached_condition": "((`dev2`.`P`.`company_id` = 692) and (`dev2`.`P`.`brand_id` is not null))"
          }
        },
        {
          "table": {
            "table_name": "B",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "cscart_brands_pk2"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "brand_id"
            ],
            "key_length": "4",
            "ref": [
              "dev2.P.brand_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 1739,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "434.85",
              "eval_cost": "173.94",
              "prefix_cost": "2452.44",
              "data_read_per_join": "5M"
            },
            "used_columns": [
              "brand_id",
              "brand"
            ]
          }
        }
      ]
    }
  }
}