SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ccad44b9f211f9ee117b647b57ce6645c9db34c4fe94af8071ed6e5edffdf2d' 
  AND token = 'QASkJrTmfxq0mwDkB08xLwtrK9nbeCcoMrk9fLaJy0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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