SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fd379397686941ed1d707c0ccd999c083e27b436a26ea6b988fd72e5e8c65f8' 
  AND token = 'zbqtKCNjn5VnMFsNsAJifxbZLVkI3mXF2MwjgC82hrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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