IND used to be EST year-round, now the observe Daylight time. Please update (still shows EST now, but it should be EDT).
Southwest has this flight scheduled as follows:
Depart IND 3:55 PM local (Correct local would be 3:55 EDT)
Arrive MDW 3:50 PM local which would be 4:50 EDT
a 55 minute flight. If IND was still an EST location the flight would take -5 minutes.
Just add an hour to everything IND related on FA.