As for the messenging api is concerned, the only token you should be using is the one issued for your bot. You shouldn't have more than one token unless you're running multiple projects. It will also need to have push notification privilege to use multicast.
Just from what you've posted, I'm not spotting any problems. Have you made sure that user U5f9a61f47f6b71696b49a7f86951d876 has added the bot as a friend and also not blocked the bot? Multicast also does not work with groups and rooms
Also, you probably don't want to reveal your access token to the public, make sure you go and issue a new one so the one you've posted becomes invalid.