SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fdf28845199d74646d83f273843976468ae8073c1dcd72a156449592dc1dc27' 
  AND token = 'tvgoPXbuvv0T0frL2cJrfcAnH1yOu9b9l2oLvlZ6jxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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