What is the quickest way to do that?
If such things as "purity" or "efficiency" are important to you, then the fastest native method is:
?,<CR>
where:
:help ?
starts backward search,
,
is your target,
<CR>
is the Enter key.
See also :help 'incsearch'
.

If you don't care too much about purity, you can enable mouse support in your vimrc
:
set mouse=a
and just use your mouse/trackpad.

The first method would be the preferred native method because it is…
- deterministic: no matter where the cursor is, the effort to get to the target is either constant (best case) or growing linearly (worst case),
- precise: the cursor ends up exactly where you want it to be,
- fast: with
incsearch
on and possibly a little sprinkling of :help c_ctrl-g
, the time to get to the target is equal to the time to express your intent,
- expressive: you basically tell Vim what to do and it does it.
The second method is rather intuitive and familiar. And it works. But pointing devices are also imprecise, and the farther the target, the harder and slower it is to acquire it. If you look at the screen capture, you will see that the pointer starts in the general direction of the target and then proceeds to make a number of adjustments to its trajectory until it lands on the target. This is too slow and random.
That sounds a bit like nitpicking but that's the kind of lossy interactions seasoned Vim users notice and try to avoid as much as possible.