SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    65103, 65454, 65102, 65596, 65597, 65683, 
    65608, 65612, 65602, 65610, 65611, 
    65598, 65873, 65965
  )

Query time 0.00086

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": 14,
      "filtered": 100,
      "attached_condition": "cscart_products.product_id in (65103,65454,65102,65596,65597,65683,65608,65612,65602,65610,65611,65598,65873,65965)"
    }
  }
}

Result