SELECT 
  cscart_profile_fields.*, 
  cscart_profile_field_descriptions.description, 
  cscart_profile_fields.profile_required as required 
FROM 
  cscart_profile_fields 
  LEFT JOIN cscart_profile_field_descriptions ON cscart_profile_field_descriptions.object_id = cscart_profile_fields.field_id 
  AND cscart_profile_field_descriptions.object_type = 'F' 
  AND lang_code = 'es' 
WHERE 
  1 = 1 
  AND cscart_profile_fields.profile_type = 'S' 
  AND cscart_profile_fields.profile_show = 'Y' 
ORDER BY 
  cscart_profile_fields.position

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.92"
    },
    "ordering_operation": {
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_profile_fields",
            "access_type": "ref",
            "possible_keys": [
              "profile_show"
            ],
            "key": "profile_show",
            "used_key_parts": [
              "profile_show"
            ],
            "key_length": "4",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 21,
            "rows_produced_per_join": 2,
            "filtered": "10.00",
            "index_condition": "(`marketpl_db`.`cscart_profile_fields`.`profile_show` <=> 'Y')",
            "cost_info": {
              "read_cost": "4.20",
              "eval_cost": "0.42",
              "prefix_cost": "8.40",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "field_id",
              "field_name",
              "profile_show",
              "profile_required",
              "checkout_show",
              "checkout_required",
              "partner_show",
              "partner_required",
              "field_type",
              "profile_type",
              "position",
              "is_default",
              "section",
              "matching_id",
              "class",
              "wrapper_class",
              "autocomplete_type"
            ],
            "attached_condition": "(`marketpl_db`.`cscart_profile_fields`.`profile_type` = 'S')"
          }
        },
        {
          "table": {
            "table_name": "cscart_profile_field_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "object_id",
              "object_type",
              "lang_code"
            ],
            "key_length": "12",
            "ref": [
              "marketpl_db.cscart_profile_fields.field_id",
              "const",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 2,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.10",
              "eval_cost": "0.42",
              "prefix_cost": "10.92",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "object_id",
              "description",
              "object_type",
              "lang_code"
            ]
          }
        }
      ]
    }
  }
}