SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4003f9df4e05ab14f66a6ee9a1fccee558d20b2b467859b29a2f4f9cbbd0a17f' 
  AND token = 'VSkS+XqxdUPdi2kblfmoG+6VRaUpy8/UGay5U27HXY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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