unattended access to a system that has no user logged in but require permission when someone is logg

Is it posible to have unattended access to a system that has no user logged in or has been locked by a user, but require permission to connect when someone is logged in? we do mantance at night and would like to have our team to have the ablity to connect to systems if no one is logged in or the device has been locked by the user. But we don't want the techs to be able to connect to a system if a user is actively using the system without the user as given them permisson.