I don't see why you laugh at this? If it's an Inter Continental Ballistic Missile (aka ICBM), it could take up to 30 mins depending on the launch of location.
Assume the scenario a warhead was launched by Russia against a US carrier group. This would immediately be detected by USSTRATCOM and it would calculate the trajectory and identify it's been launched one of its aircraft carriers. It would warn the carrier to move away from the target position. Depending on the max speed of the carrier and the location of the launch, the carrier will likely be able to escape the explosion radius.
To ensure a 100% hit chance and to take out a carrier group using an ICBM, it is theoretically suggested that it would take 6-7 ICMBs. 6-7 missiles would be simultaneously fired so that it covers all possible escape trajectories of the carrier.
Another theoretical method is for someone to have eyes on the carrier as it moves, and feed the ICBM mid-course correction coordinates. Currently no country in the world posses such technology to do this with ICBMs.
Also do not forget that usually ICBMs have an error probability rating (CEP or circular error probability). If the missile has a CEP of 1, that means it would hit the target within a 1 mile radius.
Taking all of these into account, it is highly unlikely and downright insane for any country to use an ICBM to take down a carrier group. They are for strategic targets that span a large area like cities.