I have a signed Warrant to Satisfy Judgment to be filed in connection with an Essex County Special Civil Part Jusgment that I paid off. Where do I file it and what is the filing fee?

Ask the Essex county court clerk.

Which Essex Co.?

Essex County, Ontario (https://en.wikipedia.org/wiki/Essex_County,_Ontario), Canada
Essex County, Massachusetts (https://en.wikipedia.org/wiki/Essex_County,_Massachusetts), United States of America
Essex County, New Jersey (https://en.wikipedia.org/wiki/Essex_County,_New_Jersey), United States of America
Essex County, New York (https://en.wikipedia.org/wiki/Essex_County,_New_York), United States of America
Essex County, Vermont (https://en.wikipedia.org/wiki/Essex_County,_Vermont), United States of America
Essex County, Virginia (https://en.wikipedia.org/wiki/Essex_County,_Virginia), United States of America
Essex (https://en.wikipedia.org/wiki/Essex), a county in England

https://en.wikipedia.org/wiki/Essex_County