SELECT 
  lang.name, 
  IF(
    cscart_ult_language_values.value IS NULL, 
    lang.value, cscart_ult_language_values.value
  ) as value 
FROM 
  cscart_language_values lang 
  LEFT JOIN cscart_ult_language_values ON cscart_ult_language_values.name = lang.name 
  AND company_id = 1 
  AND cscart_ult_language_values.lang_code = lang.lang_code 
WHERE 
  lang.lang_code = 'kk' 
  AND lang.name IN (
    'profile_type', 'ip_customer', 'ooo_customer', 
    'inn', 'inn_ip_text_error', 'inn_ooo_text_error', 
    'bik', 'bik_text_error', 'kpp', 'kpp_text_error', 
    'ogrn', 'ogrnip', 'ogrnip', 'ogrnip_text_error', 
    'ogrn_text_error', 'ogrnip_text_error', 
    'kc', 'kc_text_error', 'pc', 'pc_text_error', 
    'profile_type', 'ip_customer', 'ooo_customer', 
    'inn', 'inn_ip_text_error', 'inn_ooo_text_error', 
    'bik', 'bik_text_error', 'kpp', 'kpp_text_error', 
    'ogrn', 'ogrnip', 'ogrnip', 'ogrnip_text_error', 
    'ogrn_text_error', 'ogrnip_text_error', 
    'kc', 'kc_text_error', 'pc', 'pc_text_error'
  )

Query time 0.00083

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.91"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "lang",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "lang_code",
            "name"
          ],
          "key_length": "392",
          "rows_examined_per_scan": 18,
          "rows_produced_per_join": 18,
          "filtered": "100.00",
          "index_condition": "((`test_uchur_k`.`lang`.`lang_code` = 'kk') and (`test_uchur_k`.`lang`.`name` in ('profile_type','ip_customer','ooo_customer','inn','inn_ip_text_error','inn_ooo_text_error','bik','bik_text_error','kpp','kpp_text_error','ogrn','ogrnip','ogrnip','ogrnip_text_error','ogrn_text_error','ogrnip_text_error','kc','kc_text_error','pc','pc_text_error','profile_type','ip_customer','ooo_customer','inn','inn_ip_text_error','inn_ooo_text_error','bik','bik_text_error','kpp','kpp_text_error','ogrn','ogrnip','ogrnip','ogrnip_text_error','ogrn_text_error','ogrnip_text_error','kc','kc_text_error','pc','pc_text_error')))",
          "cost_info": {
            "read_cost": "10.81",
            "eval_cost": "1.80",
            "prefix_cost": "12.61",
            "data_read_per_join": "7K"
          },
          "used_columns": [
            "lang_code",
            "name",
            "value"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_ult_language_values",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "lang_code",
            "name",
            "company_id"
          ],
          "key_length": "396",
          "ref": [
            "test_uchur_k.lang.lang_code",
            "test_uchur_k.lang.name",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 18,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "4.50",
            "eval_cost": "1.80",
            "prefix_cost": "18.91",
            "data_read_per_join": "7K"
          },
          "used_columns": [
            "lang_code",
            "name",
            "value",
            "company_id"
          ]
        }
      }
    ]
  }
}