require-expiration-time allows for tokens without an
exp claim but would still check the validity of the token if present. There is no way to work around this, unless if you have control over the provider that issues the tokens and don't include the
exp claim. Instead, you could simply remove the policy and perform the validation as required by you in your backend.
Please feel free to raise a feature request to add support via an attribute for skipping lifetime validity checks.
On a side note, it would help to know why you want to skip this check. There could be a better approach to what you trying to achieve.