SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67ea477cde5f058b783337050af13700634ea0566aa994d802b3ffa97e2f6f69' 
  AND token = 'HY8uTudJlwE1tM91EX5bQPTsviDdsPd7EUAxuxCc7J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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