How do I structure a query parameter for a REST Call?

You'd have to use URL encoding to pass the json, so for example if i do a timestamp query on my QueryDataTableEntries service, my json looks like this

{"filters":{"type":"AND","filters":[{"fieldName":"timestamp","type":"BETWEEN","to":1435581955257,"from":1435553155257}]}}

Then I use this tool  https://www.url-encode-decode.com/

to get this %7B%22filters%22%3A%7B%22type%22%3A%22AND%22%2C%22filters%22%3A%5B%7B%22fieldName%22%3A%22timestamp%22%2C%22type%22%3A%22BETWEEN%22%2C%22to%22%3A1435581955257%2C%22from%22%3A1435553155257%7D%5D%7D%7D

Then my query (note this is missing the auth because i'm already authorized in the same browser session)

http://localhost/Thingworx/Things/DT/Services/QueryDataTableEntries?method=POST&content-type=application/JSON&query=%7B%…