Representatives of the European Parliament are elected every 5 years. EU citizen over 18 years of age and with main residence in Slovakia can run for a representative. If you want to stand for election to the European Parliament, you must present a statement that you have not been deprived of your right to be elected and that you are not a candidate in another EU Member State. In elections to the European Parliament, you can only vote and stand for one country.
More information is available here (in Slovak):