SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b99b966cc9e89b77719683ea3657f7fd74fe9542b497c6abbf205c30cc2aff' 
  AND token = '/8peYvyRZ5wlFvaipkHqzqQ4D6Wl4JOaSGqvPCA3D/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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