Something must be broken, because the access_tokens table should already exist and be registered as such with that Flarum version, and Flarum shouldn't try to create it again.
Can you check if you have any row in the migrations table? Are you using a database prefix, now or at some point in the past?
The easiest option would be to restore from a backup at that point. If you don't have a backup, the next easiest might be to create a data-only backup, re-install Flarum, then import the data-only backup on top of the re-created database. Last option would be to inspect the state of the migrations and manually fix the database by hand by looking at what's missing.
