SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0aa4d45a3be50243e8df473f9c780a85b8c274141319b4061b2806dcceba57e3' 
  AND token = 'NzV+Nq86bh+TcXiEmRqB9AldpuDHI5VOT8mibdheKtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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