SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e597472f522cf347fb5f3a63555624c6018ddf14923340e1ee6716ef9c13c14' 
  AND token = 'sGnZloZa12/Q+ED6vOjRkIqaZWYuPKYeM3OlUguo+tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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