SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '16c9167d5d050ac2655b8c77831c1d83a53dc3473e4ca15336bc1cfff78fb9b0' 
  AND token = 's+oqy/d3Juag/L7IdUXMY78zRwbHQpZNcMKoggiNGw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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