No.
The key is immediately active when a mobile key session is created in OpenKey HOST (manually in HOST or via an integrated PMS). As soon as the guest downloads the key, they will be able to use it to open their assigned doors (guest room, entrance door, etc.).
Adding a Guest/Sending a Mobile Key
Automated Key Delivery: Overview
Check-in day/time cannot be modified in a way that will bypass this process.
Examples:
Standard Process
A guest is scheduled to check in today. Hotel staff can either manually create a mobile key session in HOST OR check the guest in via the integrated PMS.
This triggers a "room ready" notification to the guest, who can then download the mobile key and have immediate access to their guest room door.
An early check-in/mobile key session created
A guest is scheduled to check in at 3:00 p.m. tomorrow. Anticipating a busy day tomorrow, hotel staff wants to get ahead of the check-in process. They manually create a mobile key session in HOST for this guest, using room 333, which is vacant.
Even though the guest isn't scheduled to check in until tomorrow, this mobile key session will immediately trigger the "room ready" notification. They will then be able to download the mobile key and have immediate access to room 333, regardless of their originally scheduled check-in date/time.
Check-out day and time can be modified by hotel staff.
Updating Mobile Keys in OpenKey HOST: Changing Check-out Time