I've just acquired a Noken (=no token) to unlock a supermarket trolley without needing a £1 coin. It hangs on my key ring but unlike those tokens you can get, it doesn't remain in the trolley. You insert, unlock, twist to remove and put it away. It's not circular so it's great for arthritic fingers. It cost 2.99 euros (was posted in Bulgaria so took about ten days to arrive).
www.nokens.com/
Tommy Robinson arrested. Police using their existing powers