SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10320, 10321, 10322, 9690, 10106, 10105, 
    10104, 10103, 10206, 10209, 10216, 
    10203, 10204, 10205, 10207, 10208, 
    10210, 10211, 10212, 10213, 10214, 
    10215, 10217, 10218, 10219, 10220, 
    10221, 10222, 10323, 10324, 10325, 
    10326
  )

Query time 0.00120

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": 32,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (10320,10321,10322,9690,10106,10105,10104,10103,10206,10209,10216,10203,10204,10205,10207,10208,10210,10211,10212,10213,10214,10215,10217,10218,10219,10220,10221,10222,10323,10324,10325,10326)"
    }
  }
}