SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '326b1901bc62c16c9a5cc6c19ced47c19e85691fbaf2ed44a064e5fcd537cd32' 
  AND token = 'Rgea7gGn80BVTAZKl0QYgPU5W2DagnHHRGHM/MpzgDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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