SkyEurope offers a 50% discount to all offers made before March 14. Flights must be between March 27 and June 17. To access 50% prices, enter the code "easter50" at the time of booking.
I have done a few tests and interesting flights leave 104 euros from Barcelona to Vienna and from Malaga to Prague for 124 euros. It is not what is said purely low cost but it will probably work out better than any other state company.
A note: Be careful when entering the name of the page in your search engine. The official SkyEurope website ends in .com. If you close the link in .es you will be redirected to a curious - rather shabby - page of flight search engines that seems to feed on the confused clientele of the official airline. To avoid doubts you can access from the link presented below.
Official Site, SkyEurope