which are the two countries with the flight time between them and time zone differences are equal
I'm not going to look for examples, but there will be some. More interesting is to consider the underlying geometry:

At one extreme, if you fly from north to south (or vice versa) you'll experience little or no change in time zone no matter how long you fly for.

At the other extreme, if you fly from east to west the time zones will go in the wrong direction. Depending on how you define the question there might be an "answer" in this direction, where you fly west for n hours and go back by n time zones. But for the rest of this question, let's assume you want later time zones.

If you fly from west to east, you're chasing the time zones in the right direction... but unless you have a supersonic aircraft, you can't go fast enough - you will travel east slower than the rate at which the earth is spinning, so (as long as you go far enough for more than a 1 time zone change, i.e. to get out of rounding errors) the number of hours you fly for will always be more than the number of time zones you gain.

So to match the two, you must fly diagonally : north-east or south-east. The exact angle will depend on the speed of your plane and the latitude that you start from. And then, you have to find a city along that line!