schedule event run after 2 hour

My app is an Android app for booking tables.so the app directly communicating with the server.I need to call a specific event that is generated by the Android app.say an item is purchased by the Android app, so I need to hold that item for 2 hour so no one can use that item.i'm thinking change the flag inside the database to not available. After the use that is after 2 hour I need to release the item for the other users.

I know from trigger will done the job but is it possible to delete the crown trigger from the table and remove the scheduling.