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 = 'en' 
  AND lang.name IN (
    'social_buttons.facebook_cookie_title', 
    'social_buttons.facebook_cookie_description', 
    'social_buttons.pinterest_cookie_title', 
    'social_buttons.pinterest_cookie_description', 
    'social_buttons.twitter_cookie_title', 
    'social_buttons.twitter_cookie_description', 
    'social_buttons.vkontakte_cookie_title', 
    'social_buttons.vkontakte_cookie_description', 
    'social_buttons.yandex_cookie_title', 
    'social_buttons.yandex_cookie_description', 
    'social_buttons.facebook_cookie_title', 
    'social_buttons.facebook_cookie_description', 
    'social_buttons.pinterest_cookie_title', 
    'social_buttons.pinterest_cookie_description', 
    'social_buttons.twitter_cookie_title', 
    'social_buttons.twitter_cookie_description', 
    'social_buttons.vkontakte_cookie_title', 
    'social_buttons.vkontakte_cookie_description', 
    'social_buttons.yandex_cookie_title', 
    'social_buttons.yandex_cookie_description'
  )

Query time 0.00067

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "24.01"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_ult_language_values",
          "access_type": "system",
          "possible_keys": [
            "PRIMARY"
          ],
          "rows_examined_per_scan": 0,
          "rows_produced_per_join": 1,
          "filtered": "0.00",
          "const_row_not_found": true,
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "408"
          },
          "used_columns": [
            "lang_code",
            "name",
            "value",
            "company_id"
          ]
        }
      },
      {
        "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": 10,
          "rows_produced_per_join": 10,
          "filtered": "100.00",
          "index_condition": "((`atulecarter_atul_demo5`.`lang`.`lang_code` = 'en') and (`atulecarter_atul_demo5`.`lang`.`name` in ('social_buttons.facebook_cookie_title','social_buttons.facebook_cookie_description','social_buttons.pinterest_cookie_title','social_buttons.pinterest_cookie_description','social_buttons.twitter_cookie_title','social_buttons.twitter_cookie_description','social_buttons.vkontakte_cookie_title','social_buttons.vkontakte_cookie_description','social_buttons.yandex_cookie_title','social_buttons.yandex_cookie_description','social_buttons.facebook_cookie_title','social_buttons.facebook_cookie_description','social_buttons.pinterest_cookie_title','social_buttons.pinterest_cookie_description','social_buttons.twitter_cookie_title','social_buttons.twitter_cookie_description','social_buttons.vkontakte_cookie_title','social_buttons.vkontakte_cookie_description','social_buttons.yandex_cookie_title','social_buttons.yandex_cookie_description')))",
          "cost_info": {
            "read_cost": "22.01",
            "eval_cost": "2.00",
            "prefix_cost": "24.01",
            "data_read_per_join": "3K"
          },
          "used_columns": [
            "lang_code",
            "name",
            "value"
          ]
        }
      }
    ]
  }
}

Result

name value
social_buttons.facebook_cookie_description Facebook cookies enable Facebook-related functionality, such as Facebook button on the product page. Here is <a href="https://www.facebook.com/about/privacy/previous" target="_blank">Facebook privacy policy</a>.
social_buttons.facebook_cookie_title Facebook
social_buttons.pinterest_cookie_description Pinterest cookies enable Pinterest-related functionality, such as Pinterest button on the product page. Here is <a href="https://policy.pinterest.com/en/privacy-policy" target="_blank">Pinterest privacy policy</a>.
social_buttons.pinterest_cookie_title Pinterest
social_buttons.twitter_cookie_description Twitter cookies enable Twitter-related functionality, such as the Twitter button on the product page. Here is <a href="https://twitter.com/en/privacy" target="_blank">Twitter privacy policy</a>.
social_buttons.twitter_cookie_title Twitter
social_buttons.vkontakte_cookie_description VK cookies enable VK-related functionality, such as VK button on the product page. Here is <a href="https://m.vk.com/privacy" target="_blank">VK privacy policy</a>.
social_buttons.vkontakte_cookie_title VK
social_buttons.yandex_cookie_description Yandex helps us display the buttons of multiple social networks (for example, on product pages). Here is <a href="https://yandex.com/legal/confidential/" target="_blank">Yandex privacy policy</a>.
social_buttons.yandex_cookie_title Yandex