SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef7fdc79a8d9c469975c918fa1d4bce1511da927d1cbcde1c4d5391de179075a' 
  AND token = 'EmFhI0rPyKQICAIqoIudHZ2OeQbV0IBcfC7lV09chgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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