SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '910cd6c683054546087375a8041d755f93a5689f667b437861c971130a200677' 
  AND token = 'Jpe4I6pyVDUDKDONd5gN92+NsxG13MXCbnvGTxOSZBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}