A locking device that includes: a locking element, movable between a locked position and an unlocked position and being forced to its locked position, a pin, and an actuator of the pin, the pin being configured to move the locking element from the locked position to the unlocked position when the actuator is actuated by changing the shape of a shape memory element. The pin is movable between: an extended position, in which it moves the locking element from its locked position to its unlocked position, and a retracted position, in which it releases the movement of the locking element to its locked position.