SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36cf36da0183d2057f51b8b2d6a113fe0c0fdc67179431121d620f97a6fc43ad' 
  AND token = 'sw1edYNHrWN9NRyiowf0avnOIrDALJMUchpMdeYGyUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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