SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10615, 10614, 10613, 10612, 10611, 10610, 
    10609, 10608, 10607, 10600, 10599, 
    10598, 10597, 10596, 15952, 15951
  )

Query time 0.00079

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 (10615,10614,10613,10612,10611,10610,10609,10608,10607,10600,10599,10598,10597,10596,15952,15951)"
    }
  }
}