improved_query2.sql

SELECT trip.uid FROM  (
SELECT DISTINCT st.trip_id, st.feed_id FROM stop_time as st
	INNER JOIN (SELECT s.uid, s.id, s.feed_id FROM stop as s 
	WHERE
		ST_Within( 
		    s.position::geometry,
		    ST_MakeEnvelope(
		        5.9559,45.818, 10.4921, 47.8084,
		        4326)
		)
	) as sir ON sir.id = st.stop_id AND sir.feed_id = st.feed_id
)  as sst
INNER JOIN trip ON sst.trip_id = trip.trip_id AND sst.feed_id = trip.feed_id
WHERE trip.feed_id = sst.feed_id AND trip.trip_id = sst.trip_id;