Liaison in French is a complex phenomenon. It is not systematic. The general idea is that a liaison is only made when there is a tight connection between the two words, and not made when the two words are perceived as belonging to separate parts of the sentence. There are many intermediate cases where it is optional. In these cases, the liaison tends to be made in more careful speech (poetry, or when you want to sound posh) and dropped in casual or familiar speech.

A liaison after a verb is usually optional. In this specific example, I would say [sɛ.y.ti.li.ze] in everyday speech, and [sɛ.t‿y.ti.li.ze] only in very formal contexts (it sounds affected). Offhand, I think the only verb after which I commonly sound a liaison is être: I might pronounce “Il est utilisé” [i.lɛ.y.ti.li.ze] (or [i.le.y.ti.li.ze]) in an informal discussion, but I would do say [i.lɛ.t‿y.ti.li.ze] in semi-formal contexts like a presentation.