SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d0bea7c1eb16e686519599dfbf701bacb0a0bdd85bb0b1ecd1d7cbd2e20cf28' 
  AND token = 'YuIlHlRLKg35I4J9R26TtD7uV4NCp7zjJFZPfWvRP/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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