It is EXTREMELY rare that a hotel with any reasonable amount of crew business does not provide some sort of dedicated crew lounge. These aren't as fancy as the executive lounges, but are more in tune with the crew needs. For example, a crew lounge will be open 24/7 and will probably have microwaves and a basket of apples while an executive lounge will have a happy hour for cocktail snacks and drinks.

The lounges may be dedicated spaces shared by all the airlines in residence (usually at larger hotels), or sometimes just a regular room/suite with furniture removed that is accessible to a specific airline only.

Honestly, I've had far more experience with non-crew trying to sneak into crew lounges than the other way around.