SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a15458f212224d83ac4535e4963ab8c7e67ab48118c2ce8d3c397f6a151779f6' 
  AND token = 'XJgYIxoR1in10Ysi7FtBKjVZOZhC7gLEVd/goyA11Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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