SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c710bcce9d9da6a5f9bd6fae27d085448d96d1df4d9ceca37451ee9f3756d5' 
  AND token = '1Rz7AQIWYQz3GVcUJIDXevqkhapsATRwqdzmmSXKvQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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