SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'babac8b494ba89e6c6c393b2d11d61953d765386b7b75b7e16a644b39b2ff5d5' 
  AND token = '5WDlUd3n1CyxSlLBk8cnmFRp3A2bxFYB5LSw1fErnfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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