SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf58d0673bcb943945767d0d88eb378dc269804470669c29a7d139cdb6e33e43' 
  AND token = 'zlTDHW5mT5hVzV4zfsmJoPCwpjTmrbtds05PuWeY2HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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