SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72f6bf100f288d936f00a4c131710aa84f7e0e3030ed09b070b750d5c8d92811' 
  AND token = 'QhgZBi9i8GrLAp8puTIxeirUcUwQqtSwRcOR9OjBqeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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