SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f83eb3c84c1bec78e977c45ba134e6826267f1e31b56fd957c23e689212b7132' 
  AND token = '3qIJo7u/qiyVBAfY9OJuiyxyXlKJE8morcmaHrPuN7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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