Hello. I would think 2-3 days max as small foodstuffs deteriorate very quickly.
I keep frozen food for my fish (bloodworm) as treats / supplements
I prepare this in less than a minute. Take the frozen cube from the packet, pour a little warm water from the kettle (not fully boiled, just starting to get hot) and then briefly stir for tasty instant warm food!
All thaws it in a dish within seconds and is ready for the tank