SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bed199f765d8cedc9c2d4c9d6c9bf684a581108d04493f976b1101eb1b7e31d4' 
  AND token = 'Laxdmz0GiHG1WohdnnMyqcOZ1VJbE9tnE6gwkb05+fU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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