SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '521258263859c9800a896982d97cda16578abdf6e56f917190707292f13a1979' 
  AND token = 'kxmVyNjlnE/3M7VwVduuefOwCggIWT0km3S29TjLa00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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