SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4793657c9952fcfece9e36ed935345dcf09863715aeaf145d5e6803cdc8fe99c' 
  AND token = 'GBvqSy+RRT+XyP8N7vYyeQlxlNV5MsOxs1AysBbooq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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