SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a11d3c6d3f304cd35e3fda0aa61043e0a6218d9baf427e39ecf1c9b450ba9e3' 
  AND token = 'xW3uLe+AyhwH39JDaUPs8xfVctwpPPKMD91FqrtJxXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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