SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f00364e62ac16dad397389c09bdd50d3a487b729ec2431c4725592aa724ecc6' 
  AND token = 'VIpRIBzynmVt/5uSsYOsw88ccLrgEnDv2jxqWOHrFDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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