If a security light can be plugged in and out you could say it isn't very secure.
Same with any wiring showing on the outside of the property, or indeed having the fitting low enough to be reached with a stick or tool.
Is there no way you could have the lamp higher up and bring a cable towards an up stairs room socket? Kitchens have special rules (see Wiki for info) so that's the least desirable place for a DIY electrical job.
Ideally you should run the light via a fused spur unit that you wire from a single or double socket on the ring main. Fuse would be wattage of the lamp divided by 240- so a 500w lamp would take a 3 amp fuse.
A bodge would be to buy some arctic cable (which is outside graded stranded cord flex), wire this from the fitting and feed through a hole in to the house. Hopefully you position the lamp so that there's a local socket. Fit a 3 amp plug and away you go.
if you drill any holes in to (or out od

) a building always make sure you have a 15 deg + angle upwards from out to in. This prevents water running down the cable or wall and along the cable and in to the property.
A cable should run below the hole and back up to it, on 3" or so- that's called a drip loop and again prevents damp issues.
It's a mute subject, Part P requires you to notify for external works- I believe the censuses is that providing the cable (mostly) goes straight in to the house from the light fitting it avoids the Part P requirement.
I'll just go and get my flame suit, I'm sure there will be further debate
