SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bb4c476e2e6c5b6ef8449834d3b71552f7b66b4e1243a06c58f9023b80d1c5a' 
  AND token = 'uPDcJW+OIBnIatWoieJLhiwBr96BnJHqKX9GgtozeLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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