If you want work to go fast you probably aren't very fast pasted. You may be, but most of the time from my experience, just being insanely honest, is that when I complain I want time to go fast I am not in a fast paced environment and have little to do, or its simple slow tedious work. When i'm fast paced, I almost wish time was slower because the work is so hard and fast paced. I feel like I need more time to do it.
For this, I wouldn't use stimulants. if they aren't really your thing, they suck when you're not in a play you can socialize or do something. If you are in a position you NEED to be fast paced, get a lot of work done in a small amount of time, ect, then stimulants are your choice.
Other then that I have to say opiates, or benzos depending on how you handle them. Especially ones like klonopin or especially valium in high doses. They don't hit you like a sack of bricks like xanax, and tend to cause less grogginess and last longer, but aren't really as euphoric to most. I can't work on xanax, I will move to slow and be tired and miserable. But very low doses of it (like 1/4th what I would take otherwise) mixed with like half what I would take to get high off klonopin outside of work, and time flys by past and even when I have to do shitty parts of my job they dont bother me and I get them done fast.
It's really a matter of preference. But really (tldr

Stimulants if your work is fast paced and demanding, opiates or benzos if it is a slower paced work where you are bored a lot, both of these are really really based on what YOU like though.
Really, I don't do drugs at work anymore. I may do a small dose of oxy before I go in if I haven't done any, just so I don't have any W/Ds. Sometimes dilaudid too, but I have to re-dose this while im there because after the rush the high doesn't last too long. Both of these give me a kind of speed euphoric high oddly, really while I'm at work. I guess they just make work no problem to me and not boring, I get it all done so much faster then sober and much easier. Have a lot of free time when I go in high on these 2, all other opiates make me slow and sloppy. I wouldn't take my normal dose on these before going in of course, either.