Using the AENA planning tool I can see the following departures from LTN:-
Friday 31st
GNJ57 GAIN JET AVIATION S.A. --:-- - LONDRES /LUTON (LTN) 12:55 - MADRID-BARAJAS ADOLFO SUÁREZ (MAD)
IBE2565. IBERIA --:-- - LONDRES /LUTON (LTN) 21:20 - MADRID-BARAJAS ADOLFO SUÁREZ (MAD)
Saturday 1st
IBE2843 IBERIA --:-- - LONDRES /LUTON (LTN) 11:45 - MADRID-BARAJAS ADOLFO SUÁREZ (MAD)
IBE2895 IBERIA --:-- - LONDRES /LUTON (LTN) 11:55 - MADRID-BARAJAS ADOLFO SUÁREZ (MAD)
IBE2893 IBERIA --:-- - LONDRES /LUTON (LTN) 12:30 - MADRID-BARAJAS ADOLFO SUÁREZ (MAD)
IBE2551 IBERIA --:-- - LONDRES /LUTON (LTN) 14:45 - MADRID-BARAJAS ADOLFO SUÁREZ (MAD)
I did read somewhere there was more than what's above but not seen any confirmation of these.