SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f555827cb937bb4a29a9c28d8314e8053643b7e7e6a63f5aa79286797bda3e8d' 
  AND token = 'vlikoE9xpdLapQwaS7PWd8Tnn0VfbTE48B6SGgetyDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}