No this is not a real nightclub. The building is usally used to test electric equipment
"Another graphically interesting location was the interior of a building in Prague that is ordinarily used for testing transformers and electrical insulators. Semler estimates that it is about 250 to 300 feet long with an arched concrete ceiling that is probably 80 feet high. There were massive machines with huge copper coils and cylinders that looked like something out of a weird science fiction movie. When they are in use, approximately a million volts of electricity flows through these devices that light up the room with giant arcs of light. That industrial environment was the setting for a rave club. Semler didn�t use the real arcs of light, but rather CGI with interactive lighting."
quote from www.cameraguild.com artical about director of cinematography talking about challenges of filming XXX.