SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '821e653080246674cb9f78e7e2b04a3298fd44ba9f7354af1429ac4cd05c61b7' 
  AND token = 'QEVgRwgbMsqTUUhcr0NrQ/ov+SZ2n2fEGZKr4zFGVKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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