SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '946051e7868d90e383753ea00f112dca02d2cbd6dff40fdb952ebba960af71ca' 
  AND token = 'jWAnN02dfqvy1T4gHSOmr/Ezhb/xaMZ77K4jGlULsPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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