SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ac9cbb23df57e9934fc3accaedf7b71f2d627e575f356ed75f2f5c184d3e39f' 
  AND token = 'vuuVZQQHsDW+wGhmRFdHQFuDZ2PAtqASwJP94SvYbRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}