SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9859c2b568407b88df31db3c01aba64f64b6065418a557d3fa82771f479df4ab' 
  AND token = 'W+vUhVvVuTrvZLwOLDM+HY8o4Y4I/voT6+Wfs3tLWxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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