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
