[Closed] NL4 KK scared. Should I raise river here?

I got scared on this one and not sure why? what would have been the best play?

Hand converted with online PokerStrategy.com hand converter:

Play hand

$0.02/$0.04 No-Limit Hold'em (8 handed)
Known players:
[tg]MP3$4.35:///////;CO$3.18:///////;BU (Hero)$6.19:///////;SB$4.12:///////;BB$5.24:///////;UTG2$4.00:///////;MP1$2.16:///////;MP2$10.39:///////;[/tg]
Preflop: Hero is BU with K:s, K:c.
3 folds, MP3 calls $0.04, CO folds, Hero raises to $0.20, SB folds, BB calls $0.16, MP3 calls $0.16.

Flop: ($0.62) 7:c, 3:h, 9:h (3 players)
BB checks, MP3 bets $0.20, Hero raises to $0.60, BB folds, MP3 calls $0.40.

Turn: ($1.82) 6:s (2 players)
MP3 bets $0.20, Hero raises to $1.16, MP3 calls $0.96.

River: ($4.14) 5:s (2 players)
MP3 bets $0.16, Hero calls $0.16.

Final Pot: $4.46.

Results follow:

MP3 shows a pair of tens(Th Td).

Hero shows a pair of kings(Ks Kc).

Hero wins with a pair of kings(Ks Kc).