SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    9803, 9805, 9797, 9800, 9799, 9798, 9801, 
    9802, 9806, 9804, 9809, 9810, 9811, 
    9812, 9807, 9808
  )

Query time 0.00068

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 (9803,9805,9797,9800,9799,9798,9801,9802,9806,9804,9809,9810,9811,9812,9807,9808)"
    }
  }
}