SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5610cc18c2ebeeac558ca9849ae2a74dccd8d24562efca61dab67881f6d47cb1' 
  AND token = 'kHzzxHGV2gMca6/iycill+TO9WfqKn0RMEFeifAJ5Dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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