A quick coupling for the disconnectable connection of pipelines (C1, C2) for a pressurized fluid, this coupling comprising a plug element and a socket element intended to be coupled with one another, the socket element including: - a hollow cylindrical body centered on a central axis and including an inner radial surface (S102i) and an outer radial surface (S102e) and defining a radial opening,, and - a locking element (118; 118', 118"), comprising a translatable member (118a; 118'a; 118"a; 118"'a), along a radial translation axis relative to the central axis, inside the radial opening, which is able to guide the member (118a; 118'a, 118"a; 118"'a) between a first position, in which the member protrudes inward relative to the inner radial surface (S102i), and a second position, in which the member protrudes outward relative to the outer radial surface (S102e) and in which the member does not protrude inward relative to the inner radial surface, the plug element including: - a hollow cylindrical body, which is provided to be engaged inside the hollow cylindrical body of the socket element and which comprises an outer peripheral surface (S202e) provided with a peripheral groove for receiving the movable member (118a; 118'a; 118"a; 118"'a), - a locking ring that is axially movable between a locking position, in which it surrounds the peripheral groove, and an unlocked position, in which it does not surround the peripheral groove, the locking element (118; 118'; 118") being able to drive the locking ring from its locking position toward its unlocked position when its member (118a; 118'a; 118"a) is in its second position, - means for returning the locking ring to the locking position, the coupling being characterized in that the locking element (118; 118'; 118") includes at least one elastic arm (118b; 118'b; 118"b) able to return the member (118a; 118'a; 118"a; 118"'a) toward its first position. - a hollow cylindrical body centered on a central axis and including an inner radial surface (S102i) and an outer radial surface (S102e) and defining a radial opening,, and - a locking element (118; 118', 118"), comprising a translatable member (118a; 118'a; 118"a; 118"'a), along a radial translation axis relative to the central axis, inside the radial opening, which is able to guide the member (118a; 118'a, 118"a; 118"'a) between a first position, in which the member protrudes inward relative to the inner radial surface (S102i), and a second position, in which the member protrudes outward relative to the outer radial surface (S102e) and in which the member does not protrude inward relative to the inner radial surface, - a hollow cylindrical body, which is provided to be engaged inside the hollow cylindrical body of the socket element and which comprises an outer peripheral surface (S202e) provided with a peripheral groove for receiving the movable member (118a; 118'a; 118"a; 118"'a), - a locking ring that is axially movable between a locking position, in which it surrounds the peripheral groove, and an unlocked position, in which it does not surround the peripheral groove, the locking element (118; 118'; 118") being able to drive the locking ring from its locking position toward its unlocked position when its member (118a; 118'a; 118"a) is in its second position, - means for returning the locking ring to the locking position,