SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89bf2742992e752ec8cb0f3bfefc589cc0420b40f58bbd2f8c834dbb0e70ebda' 
  AND token = 'wUhLzEeyrPvxG00YaPA6Ku77UiJ94uBsx2GLlh0ydA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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