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He lay in wait for his prey (a second ago).

He lies in wait for his prey (right now as we speak).

He has/had lain in wait for his prey (in the past).

He lay there in a pool of blood (a second ago).

He lies there in a pool of blood (right now).
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All corrrect.
The verb in the idiom "to lie in wait" is the same verb as in the meaning "to recline."

The forms you have used are:
simple past lay
simple present lies (3rd person singular)

and past participle lain
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Here is a similar thread on another site:
Lay vs Lie