EI 643 then FR 337 at Dublin
Prague → Dublin → London Luton
Timetable, Dublin time
13:20EI 643 from Prague at the gate
08:00FR 337 to London Luton leaves the gate
18 h 40 apart on the timetable, overnight
FR 337 leaves 18 h 40 after EI 643 arrives on the timetable: more than half a day, so not a connection we count.