Django: safely deleting an unused table from database
You can choose the first option. There are 3 steps should you do to complete uninstall authtoken from your Django app

Remove rest_framework.authtoken from INSTALLED_APPS, this action will tell your Django app to do not take any migrations file from that module
Remove authtoken_token table, if you will
Find the record with authtoken app name in table django_migrations, you can remove it.

Note: There are several error occurs in your code, because authtoken module is removed from your INSTALLED_APPS. My advice, backup your existing database first before you do above step
In my django application, I used to authenticate users exploiting base django rest framework authentication token. Now I've switched to Json Web Token, but browsing my psql database, I've noticed the table authtoken_token, which was used to store the DRF authentication token, is still there. I'm wondering how to get rid of it. I've thought about 2 options:

deleting it through migration: I think this is the correct and safer way to proceed, but in my migrations directory inside my project folder, I didn't find anything related to the tokens. Only stuff related to my models;
deleting it directly from the database could be another option, but I'm afraid of messing with django migrations (although it shoudn't have links with other tables anymore)

I must clarify I've already removed rest_framework.authtoken from my INSTALLED_APPS