I think this is for mineral water, dunno what is means by "bottle check". About the size of a quarter.
I don't know how old you are but in the not so distant past bottles were reused rather than being used only once like today. When you bought a bottled drink (soft drink, beer, milk, etc.) you paid for the drink plus you paid a deposit on the bottle. When you returned the bottle you would get your deposit back. In the 1960s the deposit for soft drink bottles was 3 cents. I made spending money by picking up bottles along the road and turning them in at the grocery store for the 3 cent deposit. I would assume your token was used to pay for the deposit on a bottle (or, more likely, was given to someone who returned a bottle so the proprietor would not have to give out cash - and as an incentive for the person to return to the store (or commisary) to use the token in the future).
