A lashing could meet the requirements of speed and toollessness, but maybe not the nothing sticking up requirement.
Toggles could work. Could something stick up through the middle... I'm thinking of old fashioned car air filters which typically had a round housing with a single central bolt passing through the cover with a washer and wing nut on top, but yours could just be a toggle. Maybe the hinges are not needed, that just sounds like a complication.