Impressions in GWMT vs data in GAKP

In GWMT I found a KW that has almost 10k impressions a month (although the site is ranked on 4th place, it has shows only 4 clicks, so the CTR is a joke... shame). If I put this KW to GAKP it shows that it has only 40 searches a month (all filtering off, so it's showing a worldwide result).

Is there something I am missing or simply the GAKP isn't a perfect tool and thanks to cases like this we are missing out on precious gems?

Could someone please try to shed some light on this? Because I am really thinking about building a huge project around this KW, but I am still not sure whether those are real impressions or just som bot going haywire and searching for this term all day long.