SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f325fb8418d9e767b4758ede727f478637f8a877bedeb61dc02e76fb4124784' 
  AND token = 'jzkHdPcwqGiexPHh+9qlkgYY0bUBy77mbXvp5v6JmOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}