SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    10092, 10095, 10096, 10097, 10098, 10099, 
    10100, 10101, 10102, 10113, 10117, 
    10119, 10120, 10124, 10125, 10126
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (10092,10095,10096,10097,10098,10099,10100,10101,10102,10113,10117,10119,10120,10124,10125,10126) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}