SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    9851, 9854, 10263, 10264, 10265, 10266, 
    10267, 10268, 10269, 10270, 10271, 
    10272, 10273, 10478, 9883, 9901
  )

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (9851,9854,10263,10264,10265,10266,10267,10268,10269,10270,10271,10272,10273,10478,9883,9901)"
    }
  }
}