SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85444eda3d2b7d02bcfd5b69d6f46d2d36ae05b04aa3f47bc7f02dc258b38bd1' 
  AND token = 'sF17D2KVUxKhbnbJJd0pzMpGOgkCZmw8iDbAUPLATPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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