Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c91f66989c41c87ce570d1a9d7d6ae3147908cea88b295e5dff669172776e62b' 
  AND token = 'rJEY33o8xF8Rpnn3XCylXHfAfpt6sjvf8orN3CSIQHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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