I have not read it in the Mahabharata but it's quoted in the commentary of a Kularnava Tantram verse. The verse from Mahabharata is quoted there to show that KAla or time is not merely the destroyer but it's the creator as well.
In Sanskrit the verse is as follows:
KAlah srijati bhutAni kAlah samharate prajAh |
kAlam kAlah shamayate punaha ||
The location of the verses is given as Mahabharata 1.1.209-210. It's the Haridas Siddhantavagis Mahabharata ( Edition of Bengali year 1338) they are quoting the verse from.
So, yes such a verse is present in the Mahabharata.
Note that the translation of the Sanskrit verse I have quoted is already found in your question as "Time creates existence. Time destroys, Time shatters all, and all again renews" (this is more or less a correct translation of the Sanskrit verse).
And, therefore, in the edition I'm using as the reference, the location of "Time is the root of all created beings, And uncreated. of pleasure and of pain." will be Mahabharata 1.1.208 and similarly for the remaining one.