SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59441d9997509ec7af26d8229d9dbfcaebecb5c0284dd7550d5f71d12894d287' 
  AND token = 'QNNS/wwTNelCvKIlAfel9CvF9QWXNWnSlkFDTrXls00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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