SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a7fe914b585e3bf586965dd7cc236f8a0d664ac7388205cf0df0444d36e2f8e' 
  AND token = 'ywPsjrlrrXE/iJd9UtSkOY8QzGjlDd9g7puuXJC5usg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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