A lot of the existing answers consider strictly the probability of any given cell being a mine, but seem to be missing what happens after you make a guess. You may be forced to make additional guesses, which would decrease your chances of winning quite significantly.
Of course a lot of this will depend on what you actually find, but there are some cells that seem promising than others. Below is the best I can come up with.
I'm ignoring how many mines are left (which also wasn't provided), but this can also be an important consideration.
You should pick either of the bottom-most 2 cells.
This may not seem like a great choice as it may not be the least likely to be a mine and it's not that likely to open up the board.
But nothing else being revealed will give you any information whatsoever about which of those cells you should pick, so it's a guess you're going to need to make regardless. This is always the case when you have 2 neighbouring cells containing only 1 mine with 3 mines (or a wall) on both sides.
This is objectively the best guess you can make if your goal to win.
If you need to make another guess, I'll probably suggest this:
Start off opening the cell marked "1". This should have about a 1-in-3 chance of being a mine (depending on how you calculate it, of course).
This guarantees that "2" isn't a mine either, since it's the 3rd cell next to 2 1s.
Because of the cell to the left of "1", we know only one of the cells above and below "1" is a mine. This means "1" is 1-4. If it's 4, we know "3", "4" and "5" are mines. If it's 1, this is the best case, since "3", "4" and "5" are all safe. It being 2 or 3 won't really be useful.
If "3" isn't a mine, it can either be 1 or 2. If it's 2, "6" is a mine. If it's 1, "6" is safe.
If "6" isn't a mine, it can be 1 or 2, which will determine whether "7" is safe or a mine.
If "7" is safe, this combined with "2" will tell us whether 8 is a mine, which can lead to opening up the whole upper area.
Having things work out exactly like this is fairly unlikely, but it seems much more promising than any other choice, which involves going much more into the unknown. Having that wall right next to you is good and bad: it means there aren't any potential mines in that direction, so the adjacent cells have fewer possible values, but you're also limited in how much you can open up, since you can't expand in that way.
Unless you have a more compelling guess, I'd generally recommend making a guess somewhere in a straight line next to open cells (the longer the line the better). There can be some guaranteed chains (like "2" above) and 1 cell can often give information about multiple cells behind it (like "3", "4" and "5" above).
If I need to make another guess, I may go with the cell below "1", since if the cell above "1" is safe, the 3 cells in front of the 3 below would all need to be safe, which just doesn't seem particularly likely (which may also support the above guess).