The point here is Pakistan does not have seeker based missile for more than 300km. Also, considering the fact that ships move around, generally at 50kmph in wartime, if you simply fire a missile at the direction a ship is expected to be and the ship maneuvers away by the time missile arrives, the missile terminal seeker won't spot it. So, unless you have some sort of tracked missile which tracks a moving object from hundreds of km, it is difficult to actually target aircraft carriers or any ship from long distance.
Pakistan may have the intention but not the ability to strike ships at long distances.