Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec75f24a6eb1a89614fe26663e7ac11e1542b7b59b539bc66de22b67dba652b5' 
  AND token = 'WzBcydL1qeuB/QfnNkjZMgh8CoeJ6Zl2MUyqx+xpxc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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