This was my dads token. He also metal detected, but I do not know if he dug it up somewhere, or actually got it at the store. However I do see a scratch on it so he may have dug it. It is the same on both sides.
I don't know when the first token was in use. Looks modern. The second one is an advertising piece promoting a series of competitions that Kroger stores ran in 1949. Here's one of their newspaper advertisements (27 October 1949):