SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1bad59ab473cc2c582eeda5d3071d2003dbf3d95c303be42eef70865296f8a1b' 
  AND token = 'NmaPkIZPGIjixT9ZcYpu1Db3zah0moliD0mXk3Y1npA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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