SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9323644c06eaac93bb7d383398748d8042f7b9b36e0121dab3c0437933cbe13d' 
  AND token = 'uSrmlblqhIbqQu70Ba6ETevcuPNN5wZFIaVns9FKBgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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