That would depend on the necessity of such a project. There are many factors to consider, such as where or how supplies will be transported to the facility, who will work at it, what the financial benefit would be, and the technological capability to build a McDonald's on mars.

Purely for the sake of speculation, installing any specific restaurant or store facilities on mars will require at the very least human habitation on mars to be mostly self sustaining without outside support, which means some level of terraforming or sufficient habitation systems to accommodate possibly thousands of people all of whom may not be trained scientists or engineers.

The discussion is mostly scifi at this point, as we already struggle to have people survive extended stays in orbit of earth, let alone on another planet long enough to build up a population large enough to make the prospect of McDonald's supplying franchises to the supposed colony. I imagine a lot of the limiting factors will be figuring out how to grow and process enough food to not only cover basic needs but to even make a luxury product like fast food available too.

There's also the matter of considering how or why a corporation like McDonald's would hope to benefit from such a effort. I imagine after a time the McDonald's installed on mars would become it's own mars exclusive chain since it would basically be feeding only mars population habitants and using those profits to keep itself running. Similar to how McDonald's has different divisions for different countries, mars would have it's own corporate McDonalds division that would only be linked to the main earth division by copyright and company policies and safety standards, with the profit generated being owned by the specific division that produced it. Really, this could be said for any earth origin corporation that produces facilities on mars.

Really, there's no realistic timeline for such a situation to occur, and I can only give general speculative answers based on levels of technical progress in a hypothetical mars colony.