NL25 Donk bet vs flush draw

[patoof]

How do you play this hand ?
Vilain is unknow.

I never know what to do when i raise preflop, i flop a flush draw, and the vilain donk a tiny bet, i don't know if i should raise to try to take the pot right and risk a reraise, or take the odds for my draw and maybe stack him if i hit and if he flop a monster.

Poker Stars, $0.10/$0.25 NL Hold'em Cash Game, 5 Players
LeggoPoker Hand History Converter

CO: $44.50
Hero (BTN): $28.40
SB: $24.05
BB: $7.80
UTG: $23.45

Pre-Flop: K[img]/images/graemlins/spade.gif[/img] T[img]/images/graemlins/spade.gif[/img] dealt to Hero (BTN)
UTG folds, CO calls $0.25, <font color="red">Hero raises to $1.25</font>, 2 folds, CO calls $1

Flop: ($2.85) 8[img]/images/graemlins/spade.gif[/img] J[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">CO bets $0.50</font>, Hero calls $0.50

Turn: ($3.85) 9[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">CO bets $0.75</font>, Hero calls $0.75

River: ($5.35) A[img]/images/graemlins/club.gif[/img] (2 Players)
CO checks, Hero checks

Results: $5.35 Pot ($0.25 Rake)