In general, the missile is faster over its initial distance using its rocket motor. However, the speed over ground depends on the flight path and the flight path of the aircraft. read more
There have been a couple of jets that can fly at such a speed that they can out run the target lock of a missile. So fast that they simply are nowhere near the place that the lock was obtained. One such Jet, was the SR-71 Blackbird, another jet that was planned to be on the same level of the Blackbird was one of the later planned models of the Avro Arrow. read more