SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '356534f6be8f19d70fb11740e6eda479ab6b20dcd7901ad29d8290d4830915d7' 
  AND token = '9N2fjwQ44BWftQvmkUqFBKBtwJss3U8Iof6qt4K0Ppo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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