SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4efcbdfffd5539d0a7c2a3c81af43769ab6d5bd5bd3ec1141c44021a0725f254' 
  AND token = 'kmSdj2mQl2dR/zyd1o24MARJij7YFEYWd63mR8pEYaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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