Description
According to docs, setting the TOKEN_TTL to None will create tokens that never expire.

However, before token creation, when checking that the number active of tokens of a user < token_limit_per_user, tokens without expiry date (expiry=None) are not taken into account.

https://github.com/James1345/django-rest-knox/blob/3a1bc584f9691f4bc19d8a04a98c68c293be9ca6/knox/views.py#L65

Expected behavior

All active tokens, including the latter, would be expected to be taken into account.

Possible solution

I don't know if I'm misunderstanding something, but a change like the following would suffice.

# knox/views.py
from django.db.models import Q

...

token = request.user.auth_token_set.filter(Q(expiry__gt=now) | Q(expiry__isnull=True))