SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '281c9c2f213d33479b25f84e7ec77441631a074aa673487381b59ab7583606e8' 
  AND token = 'T2gaRxZi9SwWqfyLgz/DENTnlLXGBJNeKOHQfB2hPbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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