SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '882b3d6ed259bb251121b8b44e735f0323584c248a535903aeeefc8570519013' 
  AND token = 'KoeYqM9fAfNo3I7dzWcUMjuab4JOmiQxNf323yxX+uU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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