As anyone can easily verify from a host of online video clips, ground spoilers are extended swiftly on a A320.
This
Video on Flightlevel350.com shows all three uses of the spoilers. Speedbrakes at the beginning (only seen extended and during retraction, very slowly), roll-function (only very slight deflections, but visible, especially during final approach), and ground spoilers. GS extension takes about 2 seconds.