SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '46042192f11abd45ff5d3e391ff28af0619f5ea5849c173a63e6e0bc7ee41cb7' 
  AND token = '98QJP1S7xOQSupGqRPJzgURLB75F0FzIJLi/0beR3ws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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