"it would take me 1–2 seconds"

Solution 1:

"It would take me 1-2 seconds" is correct. It takes the infinitive.

Solution 2:

• Once in the past, it took me one or two seconds.
• Previously, it has taken me one or two seconds (at most …).
• So far, it has taken me one or two seconds (and may take longer to complete).
• Currently, it takes me one or two seconds (every time, to complete).
• In the future, it will take me one or two seconds.
• If I had done it yesterday, it would have taken me one or two seconds.
• If I did it tommorrow, it would take me one or two seconds.

Solution 3:

If you are wanting to indicate how long it would have taken you to complete a task that has already been completed:

It took Stephen 10 seconds to get the right answer, but it would have taken me 1 or 2 seconds.