If you switch your classes around, it seems to work:
<div class="kooy-tomato kooy">
It seems that div[class^="kooy-"] can only find the first class and does not look for the second class for an element of type <div> , since ^ looks only at the first element of the attribute
Here is the fiddle
Whatever it was, if you try div[class*="kooy-"] * See what is contained in the attribution
Here is the fiddle
If you want to know a little more about the CSS attribute selector
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