What do I call a person doing very basic computer maintenance tasks?
Solution 1:
I'm presuming 'any key person' is derived from 'press any key to continue'.
An expression with a similar degree of derogatoriness would be 'tech support monkey' or 'IT monkey' (in essence add 'monkey' to the end of anything). Also used as 'data centre monkey' to refer to the 24/7 staff at data centres who press reset buttons etc. on demand, 'cabling monkeys' who lay cables etc.
This is British English IT related slang; I can't remember whether it translates to the US. Beware that in some countries 'monkey' might be read as racist (it isn't in this circumstance).
Solution 2:
Update:
As @abligh rightly noted, computer technician (see below), does not have the derogatory connotations the OP is looking for.
In my experience, when someone wishes to refer to computer technician with very low-level skills, one refers to him or her as the computer guy, particularly if one wants to complain about his work.
For instance,
"I've been having trouble uploading my videos all week, but the computer guy just keeps recommending that I reboot my computer and try again later."
The term technician is not inherently deprecating. But it does suggest training below the level of a scientist or engineer:
A technician is person who fixes or maintains instruments, apparatus (plural) or other technical equipment.
MacMillan's definition of technician is somewhat typical:
someone with technical training whose job involves using special equipment or machines
[e.g] a laboratory/dental technician
A computer technician or computer repair technician fixes or maintains computers, but may also play the role of an advisor or consultant to clients having difficulty with their computers.
Solution 3:
The PFY (Pimply-Faced Youth, the assistant to the BOFH. Real name of Stephen[5]) Possesses a similar temperament to the BOFH, and is often found either teaming up with and/or plotting against him
https://en.wikipedia.org/wiki/Bastard_Operator_From_Hell
Solution 4:
When, a long time ago, I held a similar position I was referred to as a "grunt", which is (AFAIK) actually an idiom for infantry man. Being compared to a soldier would not by itself be an insult, but it becomes a derogatory term when it's used by superiors to indicate your lack of status. Wiktionary describes grunt work as
"Work (especially that which is heavy, repetitive or mindless) that is considered undesirable and therefore delegated to underlings"
so that might be a good fit for your use case.