Hi Maria, I'd say getting from MK to jct 10 for Luton will take you 20 mins but it depends where in Luton you'll be working. I live just the other side of the M1 at junction 11 and work in Hitchin. If I follow the sat nav for the most direct route to work (which is through Luton) it takes me 45 minutes to do the 15 mile journey. Avoiding Luton and going through the lanes take me 30 mins.
Just something you may need to consider as I've always found Luton to be pretty bad for traffic.