Luego (Spanish for “later”) comes from the Latin locus (“place.”) From this same Latin root we get various place-related English words, including…

We can see the l‑g of luego map to the l‑c of locate clearly.

The interesting question is how “place” came to mean “later” in Spanish. It’s interesting. Basically, in ancient Latin (and even moreso in vulgar Latin), locus (“place”) was used in lots and lots of expressions related to time. So, over time, the word for “place” became more and more associated with the word for “time” — until, eventually, it became a type of time… being late. Perhaps it’s not a coincidence that the Latins are always late — stereotypically, at least!