SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e5541450d16d50012f25bc66a0026b89ee6d59a2578673d63e94c900cd611ab' 
  AND token = 'ROeBMInmZBqFX/m3JYEEjl4M5ZVMshUQlr52+ywTtvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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