SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2281a28bb75660809bee99da2a0348f17a3baf3f791b3dfade11fe451a44b647' 
  AND token = 'KQ+vtJgDXBmcnN870/HoumTaoYHlVpE/sCP+X0YA52E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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