Only way I can think of is doing something along the lines of what your wanting.
Hallway
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(3) |O| (2) (1)
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|R|
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1) Have Spawner 1 set up like this
a) When player gets near GIve the key
Set the Refract Min Max on the trigger to x min to x min
c) If this spawner triggers have it Turn in Spawner 3
2) Have Spawner 2 set up like this
a) When Player walks by and they have key remove it.
When it takes key, turn itself off.
3) Have Spawner 3 set up like this.
a) When player gets in range, turn on spawner 2.
then turn this spawner off after it turns on spawner 2.
What this would do is, when player wals to 1 and its after the refract time. The spawner will give the key. Then it will turn on the Spawner 3 behind the door. when the player goes into your room or passes the doors. it will kick the Spawner 2 on. that way after they clear that room past the door or what ever you are having them do. when they exit the room. they will pass spawner 2 which will take the key.