SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3fd4c30a696c90a255888d16c8b6d6853ac73937efe69d6755b1e924be15d534' 
  AND token = 'iIaEeFmhg9gOS49OW3Ct9WO9E9uQOK1HSZqlzHqYNIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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