getmempoolentry

curl --user myuser --data-binary '{"jsonrpc":"1.0","id":"1","method":"getmempoolentry","params":["txid_here"]}' -H 'content-type:text/plain;' http://127.0.0.1:8332/

{
  "vsize": 141,
  "weight": 561,
  "fee": 0.00001410,
  "time": 1713571767,
  "height": 840000,
  "descendantcount": 1
}