SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '667a35df07ef20d58efb9062b323559b72a43754b896d018d433b71315f6b487' 
  AND token = 'lZZYx//2wvIfzIuLRrtMqZcMMyeHzR1yD76UMQn7WPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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