SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    4725, 4726, 4735, 4024, 4020, 4028, 4037, 
    4019, 4029, 4036, 4740, 4739, 4928, 
    4493, 4495, 4496, 4494, 4909
  )

Query time 0.00032

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": 18,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (4725,4726,4735,4024,4020,4028,4037,4019,4029,4036,4740,4739,4928,4493,4495,4496,4494,4909)"
    }
  }
}