just to provide a data point here. I arrived at the KLM /AF lounge at 5pm and success.

No doubt helped by the fact that there were all of five people in there! The attendants were obviously setting up for the evening. But even at its peak (730 ish) the lounge was only about two thirds full.

Good choice of wine, beer and five spirits. Food was ok (one hot meal) but the lounge was a bit cramped; mainly because most of the seats are at tables.