SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f36bf96fc3e20295e517e5260949d14124176a47856cb3fd36425bedc390bee' 
  AND token = '+Bdymfh9cLnRv6tgzM3AcwckgpkJqMe+yeBIyU5g/tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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