SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08354425056f4381f39850b45559f79c9c951442d346d451ed1bbabb38ddcb9b' 
  AND token = 'vvZIPlZhQ4W/kYsX0yR+uSTKDcg90kXBDHiQ+CtrxhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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