A line in a drama "Van Helsing"

I'm a student from Korea. I was watching the drama Van Helsing, and I came across the following line, whose meaning I do not understand:

Might as well be on the other side of the moon, all the good it does in here.

Literally translated, the Korean subtitle says:

Come to think of it, I'm relieved to be in here.

Is this translation right? Does it even make sense?

Solution 1:

This is the passage in question:

I miss Kit Kats.
That little chocolate candy with the cookie thing in the middle and it goes snap when you break 'em.
Click, click, click I miss Kit Kats.
Probably a ton of 'em out there, too, just sittin' there in stores.
Might as well be on the other side of the moon all the good it does me in here.

What the speaker is saying is that, in her current situation ("in here"), the stores which have the Kit Kats are as easy to get to as the other side of the moon: in other words, impossible to get to.

This has the opposite meaning to the given translation of "Come to think of it, I'm relieved to be in here". The speaker is in fact unhappy to be there, because it's stopping her from getting a Kit Kat, which she is craving.

So, it's a very bad translation.

On further reading, it seems like the speaker is in some sort of survival shelter, where she (and possibly others) are sealed off from the outside world for their own protection. Earlier in the passage, she reminisces about going to fast food stores with her family, and later in the scene, it appears that some desperate people are trying (fruitlessly) to get in, in order to avoid some sort of terrible fate (eaten by vampires?).

This actually colours the translation a bit. The speaker is presumably relieved to be in there generally speaking: it sounds nicer than whatever happened to the people trying to break in. But in that exact moment where she's craving Kit Kats, the translation doesn't make sense. At that moment she is focussing on one of the aspects of being in there which she doesn't like – that she can't go to a shop whenever she wants.

Solution 2:

I have a machine next to me, and it contains the exact answer to your question. However, it is broken and will never work again.

Do you want me to ship the machine to you, so you can have it?

An appropriate response to give to that question would be "Might as well ship it to the other side of the moon, all the good it does having it."

In other words:

I don't care where you send it to. Even if you send it somewhere I can't use it. I wouldn't be able to use it even if I had it right here.

I can't think of a single scenario where this can mean the same thing as "Come to think of it, I'm relieved to be in here."

However, if you can add the context in which it was said, maybe there is a reason for this translation to be appropriate.

But I highly doubt it.

edit as per the context provided in another answer, I'm going to say that this subtitle translation is wrong. There's no argument to be made for this being related in any way to what is being said.

This seems to be a misinterpretation (or lack of understanding) by the translator.

Solution 3:

I presume the "it" referred to in your quote is something (a tool, perhaps) which is available to the protagonist(s). The phrase means that the "it" is useless to them and hence it might aswell not be available to them.

Let's say the protagonists were locked in a room with no light and "it" was a set of written instructions describing how to escape this room, since there is no light in the room the protagonists have no way of reading these instructions so the instructions are useless and they may aswell not have them.