SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40fb9739a46f8bf1b519919705066b7f113a4412fff39a70eb791d09a76f6b40' 
  AND token = 'FFmkcZt3QpwamlXe3wjC1eOob4sFg8Y3qm/Faxqq+IM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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