a homophone giving the same meaning when used in a phrase....

Well, I can't disagree with that, stales, but I think it is happy coincidence, nevertheless - I have come across the phrase in C19 literature where the context equates closely to Jackie's excellent thesauric contribution.
"Tokens" were well known in that period (and earlier) as a substitute for money, to be spent in "the company store" only. But these would not be bought, only used to buy things - analagous to caradea's idea of putting tokens in a machine.
But I feel that the alternative meaning of "evidence", or a "sign" is the more likely source of the meaning of this phrase.

What an excellent thread! ta, stales!!