SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eeb05973fc41e6543855aa12ce11d232e5947fb38af4bf36839fe3bf382a545' 
  AND token = 'qjg6r7RSr4pWJcxNJR3sbSykA9VuQXZtZH13SFbFSGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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