Well, if you've participated in 5 kills, let's break that down:
First off, in said example, you've died zero times. So lack of proper time in lane isn't an issue. There is more likely something wrong with your reaction to getting an advantage or potential advantage.
You've been a part of 5 kills, and in a typical bot lane scenario, that would mean that you and your support probably got a couple and your jungler was part of a couple too. So let's be fair and say 2 of your assists were solo assists and the other 3 were shared between 2 people. So the 2 solo assists equal 300 gold, and the 3 shared assists would come out to 225 gold. So that score in and of itself is nearly equal to being 2/0/0. If one less assist was shared with the jungler, then you would truly bee at 600 gold, or 2 kills.
To expand on the above paragraph, let's now determine the amount of advantages you capture from this. Since your score is 0/0/5, we know you haven't died. And if you got that many kills bot lane, you get a chance to free farm or shove the wave and get dragon. And if you've gotten that many kills bot lane, you've probably taken the tower as well. So that alone should equal a nice CS lead and tower gold lead too. Most of the time, first tower blood happens in the bot lane when there are 5 kills picked up down there. Not to mention the dragon buffs you come across - they vary but most are worth something in the game.
The only circumstances that would cause you to be even in CS is either you don't properly shove the wave before a back or you get chased by their mid laner every single time you get a kill. But this is very unlikely to happen and you still escape with such a score.
The point I'm making here is you're still getting fed even if you don't get a kill and go 0/0/5. You still get gold, free experience, dragon buffs, and extra time to CS while the enemy is dead or backing. You should be up by at least 20 CS and have their tower if your score is 0/0/5. And you'll be drawing a lot of attention bot, meaning your team will be securing towers and leads also. And their tower takes lands gold in your pocket, too.
tl;dr being 0/0/5 means you're still in a great spot, gold-wise, and should be fed enough to make an impact.