SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934c86491bbee2d79e9b90239b0afc390c9c406b7cd0784cc6323802b85e98a3' 
  AND token = '0KAp/ODcOHOw42ns1aKAkO/yZxUJaaeJ1XZKVSFQBxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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