Hi Clarisse,
Hopefully I understood you question correctly.
So the hash functions are one way only, meaning once you hash the token you can't get back to the token from the hash it self (as opposed from encryption where you can both encrypt and decrypt).
In the database, only hashes are stored, so that even if the database gest compromised no one can get the actual tokens.
So if you look on the database for any token, they won't be found. The only way is to hash the token first and then search the database for the corresponding hash.
Best Regards