SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fb355694b58e09d56ad19431a44ba1358bfea5a094258f93208fe75b2d32a6a' 
  AND token = '7qNYF/zQiiJF9Pp1mv68wShJgFG5slRJDZZ7obp6HE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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