As DL PM you will be SkyTeam Elite+ with access to Sky Priority lines/ lanes for check in, passport control, and security.
Checking in at anytime between 5.45 am and 6 am should give you enough time to go through security, passport control, then get to KLM Lounge/ Club 52 for a quick breakfast, and then get to your gate at 7 am.
You will have to undergo another set of security questions and carry on bags and body scan before entering the secured gate area.
Boarding usually begins at 7.10-7.20 am.,