SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ca2e76cc6741447f2f9c23554d4d939827221297875eee554eebd7310229418' 
  AND token = 'DTKGc7bveYroiw8mCbuvZoO6tfFw8ktwQ7XaG80vm/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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