Payment tokens are very common. Usually they're sold as keychains, wristbands or rings, and they're provisioned to work with the myriad of payment processors out there - which aren't banks.

in my case, it's a token from iCard. The way it works is, it's connected to a regular bank account number with an IBAN number (supplied by iCard when you activate the token), and you transfer money to it that you can then spend with the contactless token. The nice thing is, if you lose it, you can't lose anymore money than you put on it.