SELECT 
  lang.name, 
  lang.value 
FROM 
  cscart_language_values lang 
WHERE 
  lang.lang_code = 'ru' 
  AND lang.name IN (
    'abt__ut2.add_to_cart', 'sign_in_to_buy', 
    'text_login_to_add_to_cart', 'abt__ut2.add_to_cart', 
    'sign_in_to_buy', 'text_login_to_add_to_cart'
  )

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.73"
    },
    "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": 3,
      "rows_produced_per_join": 3,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "2.43",
        "eval_cost": "0.30",
        "prefix_cost": "2.73",
        "data_read_per_join": "1K"
      },
      "used_columns": [
        "lang_code",
        "name",
        "value"
      ],
      "attached_condition": "((`dev2`.`lang`.`lang_code` = 'ru') and (`dev2`.`lang`.`name` in ('abt__ut2.add_to_cart','sign_in_to_buy','text_login_to_add_to_cart','abt__ut2.add_to_cart','sign_in_to_buy','text_login_to_add_to_cart')))"
    }
  }
}