SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '125392fb483d7bfae88f3a4cc1639ac51136ff92b87035687176643c6d792091' 
  AND token = '/+mBub08HlIvFCXYzVdRdhhebs/C8zjsSbRSTVuzGvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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