SELECT 
  lang.name, 
  lang.value 
FROM 
  cscart_language_values lang 
WHERE 
  lang.lang_code = 'en' 
  AND lang.name IN (
    'cls.show_more', 'cls.show_all', 
    'cls.total_found', 'cls.featured_products', 
    'cls.found_products', 'cls.browse_products_by_category', 
    'cls.back_to_all_cats', 'cls.storefronts_categories', 
    'cls.text_pages_and_blog', 'cls.brand_pages', 
    'cls.vendor_pages', 'cls.porpose_correction', 
    'cls.popular_searches', 'cls.found_categories', 
    'cls.product_code', 'cls.enter_more_symbols', 
    'cls.nothing_found', 'search_results', 
    'cls.quick_view', 'cls.add_to_cart', 
    'cls.add_to_wishlist', 'cls.add_to_compare', 
    'cls.user_last_queries', 'cls.select_product_options', 
    'cls.auth_users_only', 'cls.show_more', 
    'cls.show_all', 'cls.total_found', 
    'cls.featured_products', 'cls.found_products', 
    'cls.browse_products_by_category', 
    'cls.back_to_all_cats', 'cls.storefronts_categories', 
    'cls.text_pages_and_blog', 'cls.brand_pages', 
    'cls.vendor_pages', 'cls.porpose_correction', 
    'cls.popular_searches', 'cls.found_categories', 
    'cls.product_code', 'cls.enter_more_symbols', 
    'cls.nothing_found', 'search_results', 
    'cls.quick_view', 'cls.add_to_cart', 
    'cls.add_to_wishlist', 'cls.add_to_compare', 
    'cls.user_last_queries', 'cls.select_product_options', 
    'cls.auth_users_only'
  )

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "lang",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "392",
      "used_key_parts": ["lang_code", "name"],
      "rows": 25,
      "filtered": 100,
      "index_condition": "lang.lang_code = 'en' and lang.`name` in ('cls.show_more','cls.show_all','cls.total_found','cls.featured_products','cls.found_products','cls.browse_products_by_category','cls.back_to_all_cats','cls.storefronts_categories','cls.text_pages_and_blog','cls.brand_pages','cls.vendor_pages','cls.porpose_correction','cls.popular_searches','cls.found_categories','cls.product_code','cls.enter_more_symbols','cls.nothing_found','search_results','cls.quick_view','cls.add_to_cart','cls.add_to_wishlist','cls.add_to_compare','cls.user_last_queries','cls.select_product_options','cls.auth_users_only','cls.show_more','cls.show_all','cls.total_found','cls.featured_products','cls.found_products','cls.browse_products_by_category','cls.back_to_all_cats','cls.storefronts_categories','cls.text_pages_and_blog','cls.brand_pages','cls.vendor_pages','cls.porpose_correction','cls.popular_searches','cls.found_categories','cls.product_code','cls.enter_more_symbols','cls.nothing_found','search_results','cls.quick_view','cls.add_to_cart','cls.add_to_wishlist','cls.add_to_compare','cls.user_last_queries','cls.select_product_options','cls.auth_users_only')"
    }
  }
}