SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afad284ecdf135f99a79a30a0df279798a4b4b90232bc03c1fd42e857625e698' 
  AND token = 'p2/oD5X6uoVKeUUjKvuggQ6tJNmmWFV2Zy8yHOU6+mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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