SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcbc7254482d95baf1fa4088102f9f746ca7d8065548002434dbaba54dc93559' 
  AND token = 'YfhfKZDL3GKP2n8tlqpI7QXflPnpBVlE9jcTgppZh/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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