Yeah you can find a couple;
There are a total of 3 Heart Scales in Kalos Route 8
Mountain Level; thin path on right side of Ambrette Town Pokémon Center, follow all the way to the end.
Coastal Level; west of the stairs, buried in the sand (hidden, reappears occasionally)
Coastal Level; in a rock south of TM19 (requires Surf) (hidden)
You can get one in Coumarine City
In the Hilcreast side of town, after defeating the Champion, Tierno resides on the cliff edge. Each day, he will ask to see a Pokémon with a dancing move. If the player shows him one, he will give a Heart Scale.
One in Frost Cavern
East of the waterfall on the lower level (requires Surf and Waterfall)
One in Azure Bay
On the western part of the route, among the five non-breakable rocks surrounding the Advanced Tips sign, inside the northwestern boulder (hidden)
Additionally you can find them with the Pickup Ability
Level 51-60 - 3%; Level 61-70 - 5%; Level 71-80 - 10%; Level 81-90 - 10%; Level 91-100 - 10%
You can buy them in the PokéMile Seller for 125 PokeMiles per Heart Scale
And yes like you said, you have a 50% chance of finding them on Luvdisc, so you can steal it from them/catch them.
Source: Bulbapedia and Serebii