SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985475a6a3b5d9808ba8ede115b3e256a533719d6134aece1bbc940ee951d611' 
  AND token = '9KFyyeDRDCIMQ0kwlMnduKq3O+Am1l7fvOV+hMRnekQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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