SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2b99c585fc4656cdc0bcd497bf240057db461c29856df113edd30479e31780f' 
  AND token = 'TgLDbBPpIgLYoNHOmIGjG/+jijHNrcY8eOFAZ5n/fQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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