Get stock searching by timestamp
I have a cron to read product changes in LS DB and sync with my website and other platform. I use this cron only with modificated products in last 30 minutes, using timestamp query parameter. This works fine when someone modify a product in LS, but when LS sales something and change product stock (inside ItemShop) it doesn't refresh product timestamp and I don't get this important modification in my cron request.
How can I get the item stock (qoh) after LS sale, without asking for all products, using something like timestamp.