The law doesn't spell out that you have a key to the unit, only access to it. For all the law cares you might have a passcode, retina scan, or button or other non-key device to gain access. But if you agree in your rental agreement that the access requires you to ask a front desk employee then it's solid as far as the law is concerned.

"The law" is a thing that is going to be interpreted and enforced by a human judge, one who is likely going to frown upon a landlord's creative interpretation of it.

A judge's job is not to apply the law to the letter, but to the spirit. They are not going to throw their hands up when a tenant is kept out of their unit, no matter what the landlord might have decided to sneak in into the rental agreement: the law is there to protect the tenant.