The JWT TTL can be configured per application, so if you were using a different application for OIDC vs an API - then you could do it.
But if you don't want to use multiple applications, then it is not possible, at least currently.
I could see a use case for asking for a JWT with a TTL equal to or less than the configuration and that request being honored, that could be a feature request. But as of right now, the only option is different applications.
