SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '468e2d97989413bddc1325fecfa33257e3f9d064c893cba8d71c57c454cac4fa' 
  AND token = 'NvltxrwyelUC85gaKmVwPO89esFkDM+NVLnS1uHzhKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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