The summer schedule is pretty much set now.. It looks like a 5AM flight is added from 15 JUN onwards, probably to cover the increased summer loads. There is a small chance that they will change the schedule and add this flight from an earlier date...but I would not count on it.
Also, even if they would add it - it is not guaranteed to cost 55 euro. Prices differ per individual flight, it is not the case that every 5:00 flight always costs 55 euro and every 8:20 flight always costs 88 euro. Depending on how many people are interested in the flight it may be much more expensive (or cheaper).