SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72d8ac2a694c415ec1b1634eb592ea754e52bfcea923aca39f37ea9e80bd207f' 
  AND token = '3HSoNxUjnDejY51nao3U2kdFayGRGIQ4p/IjM8O8JCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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