SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ebb286f7b3031abd03453ca948b15705dc6c50ad273b38150debc35770afb537' 
  AND token = 'Acb4lja8uvz2zrODTVrd0o4OLHF3Nnj5n5+5xgEQltU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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