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 = 'en' 
WHERE 
  1 = 1 
  AND cscart_profile_fields.profile_type = 'U' 
  AND cscart_profile_fields.profile_show = 'Y' 
  AND (
    cscart_profile_fields.field_type != 'E' 
    OR cscart_profile_fields.section != 'C' 
    AND cscart_profile_fields.field_type = 'E'
  ) 
ORDER BY 
  cscart_profile_fields.position

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.041022106,
    "nested_loop": [
      {
        "read_sorted_file": {
          "filesort": {
            "sort_key": "cscart_profile_fields.position",
            "table": {
              "table_name": "cscart_profile_fields",
              "access_type": "ALL",
              "possible_keys": ["profile_show"],
              "loops": 1,
              "rows": 39,
              "cost": 0.0172118,
              "filtered": 38.46154022,
              "attached_condition": "cscart_profile_fields.profile_type = 'U' and cscart_profile_fields.profile_show = 'Y' and (cscart_profile_fields.field_type <> 'E' or cscart_profile_fields.section <> 'C' and cscart_profile_fields.field_type = 'E')"
            }
          }
        }
      },
      {
        "table": {
          "table_name": "cscart_profile_field_descriptions",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "12",
          "used_key_parts": ["object_id", "object_type", "lang_code"],
          "ref": [
            "u985510652_ecartify.cscart_profile_fields.field_id",
            "const",
            "const"
          ],
          "loops": 15,
          "rows": 1,
          "cost": 0.0142358,
          "filtered": 100,
          "attached_condition": "trigcond(cscart_profile_field_descriptions.object_type = 'F' and cscart_profile_field_descriptions.lang_code = 'en')"
        }
      }
    ]
  }
}