Index for the Departures Board

The departures board of every airport runs this query hundreds of times a minute:

SELECT flight_no, scheduled_departure, arrival_airport, status
FROM flights
WHERE departure_airport = 'SVO'
  AND scheduled_departure BETWEEN '2017-08-15 06:00' AND '2017-08-15 12:00'
ORDER BY scheduled_departure;

The flights table has no indexes yet. Create one index that serves both conditions of this query and its sorting.