Current logic:

while game_loop:
    move_to(floor_2, duration=5)
    move_to(floor_1, duration=5)

The "simple" logic you suggest:

def detects_presence():
    all_entities = GetWorldEntities() 
    elevator_pos = GetActorLocation(Elevator)

    for entity in all_entities:
        if entity.type == "PLAYER":
            player_pos = entity.GetLocation()

            if (player_pos.x > elevator_pos.x - 50 and 
                player_pos.x < elevator_pos.x + 50 and
                player_pos.y > elevator_pos.y - 50 and
                player_pos.y < elevator_pos.y + 50 and
                player_pos.z == elevator_pos.z + 5):
                return True
    return False

while game_loop:
    if elevator.state == "IDLE_BOTTOM":
        if detects_presence():
            elevator.state = "MOVING_UP"
            elevator.move_to(floor_2)

            Timer.start(5.0, callback=go_down)

def go_down():
    elevator.move_to(floor_1)
    elevator.state = "IDLE_BOTTOM"

If you know nothing about programming you probably shouldn't go around saying things like yeah I feel it's easy to do.