SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60c16438aa39138ec089bc99e7b5624fa3b3965e7be87a8ac14415089af180f7' 
  AND token = 'jkNaHsYtNNTZ9rxo1InDEQE3iR+VIMVVnRwR3+7B9aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}