SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4da8677f4aae027d3165cd8065cb548a9b1e4db861ae72b65fa12d42a7b6c6c' 
  AND token = 'kSTL8rfswfxTxo8zdTj84XMttfd8EkX+KhSTXWXBulU=' 
  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"
    }
  }
}