SELECT 
  lang.name, 
  lang.value 
FROM 
  cscart_language_values lang 
WHERE 
  lang.lang_code = 'en' 
  AND lang.name IN (
    'my_account', 'orders', 'profile_details', 
    'sign_in', 'register', 'sign_in_to_get_more_offers', 
    'categories', 'my_account', 'orders', 
    'sign_out', 'my_account', 'orders', 
    'profile_details', 'sign_in', 'register', 
    'sign_in_to_get_more_offers', 'categories', 
    'my_account', 'orders', 'sign_out'
  )

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.01470144,
    "nested_loop": [
      {
        "table": {
          "table_name": "lang",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "392",
          "used_key_parts": ["lang_code", "name"],
          "loops": 1,
          "rows": 8,
          "cost": 0.01470144,
          "filtered": 100,
          "attached_condition": "lang.lang_code = 'en' and lang.`name` in ('my_account','orders','profile_details','sign_in','register','sign_in_to_get_more_offers','categories','my_account','orders','sign_out','my_account','orders','profile_details','sign_in','register','sign_in_to_get_more_offers','categories','my_account','orders','sign_out')"
        }
      }
    ]
  }
}