Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c9ada69e6e1efe525f7ac5a5bd5c2f24eaae7d162b514865cdb4bde8bca3d93' 
  AND token = 'OKzLq21kyjgKSdi/1eC1pHnyJqKCVhA/NdrgtSiWkgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}