"Narcos" star Pedro Pascal is riding the wave of popularity, yet he says the Netflix show can't go on unless there's a way of protecting cast and crew.

We got Pedro -- who plays DEA agent Javier Peña -- out at LAX Sunday and asked about the respected location scout who was murdered in an area near Hidalgo.

As we reported ... Carlos Muñoz Portal's body was found earlier this month riddled with bullets. Muñoz was scouting in Mexico for season 4 ... where Peña zeroes in on the Mexican drug cartels.

The way Pedro sees it, everyone's a target now, so something has to be done.