SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22d6ebd464f0a51e3bb19398a4712c577e9348fc36e1f122ca5c35899e540e63' 
  AND token = 'gZnJBUsDxzo+gtrIGHOgwV5W3vkSlZy/RpLE08fiG2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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