SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9911091137bae7a4988b8f58d7a85b78119417bdf817c72fc7d71c6da6e2664b' 
  AND token = '5y8ofvyHzyG7tjqqdKVcxaC34b4ZjZZvu2sRvQ/tJwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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