For example:
JQL query '{project = "ope"} AND {priority in ("blocker")} AND {key in ("ND-1068")}'
First off the brace ('{', '}') is a reserved character in JQL. So what does it mean here?
And if you ignore the braces, this means nothing since, obviously, "project =ope and key=nd-1068" is a null set (no key in ope would start with 'nd-').
These queries are usually slow and occasionally associated with other problem so understanding where they come from and what they are for would help me understand how to mitigation some of the problems.