Battery usage for locking already locked door?


I have a stupid question:
I am running a HomeKit automation every 4 hours which turns off all lights and devices and locks nuki if nobody is at home. It’s working fine and I can see it in nuki protocol.
But now my question: Does it waste battery if I send a “lock command” to an already locked nuki smart lock? I think the most battery is used by the electric motor to rotate the key, which is not necessary in my case.
But does it also waste battery of the nuki smart lock to receive and interpret that “lock command”?
Or this there always some traffic between HomeKit hub and nuki smart lock and my additional commands don’t waste any battery?