Short answer, I'd say Hollywood early midieval Europe…
The arms and armor are based on European designs (as is the village architecture [at least through 1.13] and professions), which is unsurprising given the background of Persson.
With the various fantasy elements, trying to assign an accurate historical time correspondence dosen't seem to be an objective exercise, but IMO the 'feel' of the base game is roughly 8th century (Charlemange-ish)… with added magic [RS fits well enough as magic under Clarke's 3rd law]
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WARNING: I have an extemely "grindy" playstyle; YMMV — if this doesn't seem fun to you, mine what you can from it & bin the rest.
I think you answered your own question: Minecraft is anachronistic. Much of Minecraft seems to be set in a time before the Industrial revolution. But then there are elements which are clearly from the post Industrial era. Redstone clearly mimics late 20th century technology. All the alchemical elements suggest anything between Classical Age and early Renaissance. And then there are all the fantastical elements like zombies and animated skeletons which never existed in anyone's timeline.
If you don't like that I'll second ScotsMisers Redstone assessment, but the fantastical elements still pull the game out of any realistic timeframe.