SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ced0398d467c558ff5f84c6f69fe780e40492c28bbc21a2d4cd858ffb5a6a20' 
  AND token = 'WxMC0ZNDlAfclQW2nKHg2THzePsQ6DkBYwm6d6rDxXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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