Tri-rail to Miami international Avianca flight timing

Hey folks I have a flight this Wednesday supposed to be taking of 8:15AM and will be taking the trip rail from deerfield beach which is an hour and 10 minutes im trying to figure out if I should be taking the train ride that will get me to the MIA Airport at 6:45 or the one that will get me there 7:15?

I know I need to take the Miami mover from the trainstation but I do not need to check any bags in but have never flown through MIA and of course do not want to miss my flight. How long does it usually take to get through TSA this early in the morning? thanks