SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    10180, 10181, 10182, 10187, 10190, 10193, 
    10196, 10197, 10208, 10209, 10216, 
    10217, 10221, 10224, 10226, 10227
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00974

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 (10180,10181,10182,10187,10190,10193,10196,10197,10208,10209,10216,10217,10221,10224,10226,10227) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}