SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60532d9b9209d4b6a5743d88ff891e4a6e3003e56b576d9fbc58be27eb987cba' 
  AND token = 'xQhpdgi4qLWXHVn3jzu2aHxN+pUs1bCbITO/z8ZDF+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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