SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09fa40039eade7ec12817876d208f3390003eabeda0a57a530a2ac49830d3b3a' 
  AND token = 'xNupIPkgOTbr2uueDuzjKoatui9mD3G3hbc9UBecUJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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