SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    4135, 4814, 4819, 4820, 4821, 4818, 4816, 
    4822, 4817, 4815
  )

Query time 0.00029

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": 10,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (4135,4814,4819,4820,4821,4818,4816,4822,4817,4815)"
    }
  }
}