SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8ce588a0b6c56d85d59a91024f89fdc81ae1cd751edaeb44817bf9985986bb3' 
  AND token = 'YpJ6uFk3q/OLyZ7PXPJSDR5nu+xI9mbGjjnvAZ/zhhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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