SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8f89fc5fbc721bd26003d1274015eeaca3da58732a0c9bc6897c6c72b5d2e5f' 
  AND token = 'YlZ5DAnbGu6DPteiwe7DgUNkokBOuL8Genipeu8ZDj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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