Do you think mind control technology would be possible? How long do you think it would take to be invented? (propaganda and indoctrination does not count, I mean actual mind control)

It's an interesting thought, one that has crossed my mind a time or two.

I think in reality, we don't have anything that is "absolute" mind control, but we come pretty close through long-term exposure to biased information (propaganda). You asked for this to be an exception, so I won't go into details there.
There is a famous study done by Olds and Milner in the world of psychology, where they hooked up rats' reward center in the brain to some electrodes, resulting in incredible change of behavior. The rats were stimulated by them pulling a lever, and this felt so rewarding to them that they couldn't think of anything else. After the stimuli was given, they kept pulling the lever to exhaustion, not even prioritizing food or sleep anymore. The scientists also attempted the reverse; to inhibit the reward system. The rats became lethargic, and didn't have motivation to do anything at all, not even eat.

This is, to much smaller degree, effectively the same that happens with humans that are addicted. Whether it's to gambling, porn, drugs, gaming, or social media.
So if one can spontaneously create an addiction in someone, you're one step closer to mind control.

One show that caused a bit of a psychological unease with me was first season of Jessica Jones, where David Tennant makes an excellent performance of a character who can make anyone do exactly as he says. I think this is the kind of mind control that we fear, where we are completely aware of ourselves, but cannot help but do what we have been commanded to do.

Edit:

I forgot to answer your question: Yes, I think it will be invented (and to some degree already has), and total mind control is probably at least 50 years away, as we research the psychological basis that was found with the aforementioned research.

We already have it. It's called targeted advertising. Also, tik-tok

I think it's plausible right now. We have brain-computer interfaces under active research (for things like stroke recovery or limb-loss patients).

At the same time, neuroscience researchers have been able to switch off parts of the brain temporarily to study things like how the Wernicke area affects our use of language.

You could probably combine the two for something that fits the bill.

That being said, what I'm envisioning is more along the lines of "strap the victim into a chair and hook them up to a lot of fancy equipment for a reprogramming session" than "point a remote at the victim and press a button".

Still, it's pretty spooky to think about.

The problem is first getting past the hurdle of defining what mind is and how consciousness works. Hell, we still don't know much about our brain at all. Most of our mental health medications were found as a result of unexpected side effects. The brain is too complex and risky for us to understand easily, and to go into the metaphysical world of consciousness would be even more challenging. I am more interested in the consciousness uploading part of possibilities. This will 100% be abused by corporations, but in theory, you could be "alive" in virtual worlds even after the death of your physical body. We could be in one right now and not be aware of it. Once we come to a conclusion on the philosophical questions, we can then look into the physical and psychological.