SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7231bf48f06669a4740f3ca9f8d05eaaf936ffb1f2d31c3d6032bac987499678' 
  AND token = 'RjZgVtu4l83xDSwnxs2iZnmHEQbCQzqJa6hhlSuM4Gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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