SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9727f4bf52263f52e85458e9822933703a039c0eef31ccb8cd1c9c29304d16a0' 
  AND token = 'z99rAxJKRm0KId/TzULpSCSVp3vvGHDm/+pKAsVby4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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