Just in case you are abiding the TOS and still think that there could be a problem with CTR. Adsense would not be having problem with high CTR. Users will note that once their CTR gets high, their cost per click might reduce to a large extent that the eCPM also decreases rather than increasing. In case you are using adwords to get traffic, Adsense might be having problem IF You are earning more from Adsense than what you spend on adwords. Example You put 1$ in adwords and made 2$ from the traffic then adsense might take this into notice. This becomes a problem ONLY when your CTR is high. Otherwise High CTRs on Search Traffic are fine.