Especially since it seems to only take the Enterprise a couple of minutes to get from Earth to QonoS (Voyager could have been home in a weekend!).
I think the Enterprise uses a quantum slipstream or transwarp drive in the reboot. Its the only workable explanation for the travel time to Kronos.
The Vulcan travel time in the last movie is ambiguous but I think a few hours. Still really fast. It indicates Kronos is either way closer to Earth than Vulcan or the Enterprise has upgraded its slipstream drive this time
I think its about 0.75 light year per second for Earth to Kronos based on 90 light year distance. So 75000 light years for Voyager at Star Trek Into Darkness speeds would take a day or so. The whole galaxy is within a days warp.
If the Enterprise warps into the cosmos away from Earth at Star Trek Into Darkness speeds for 3 years of its 5 year mission it will travel: 71 million light years.