SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b41f5709b43df7fbfe5b19b05cb55bdf0fa05b23663fbbd69e2291b33af42796' 
  AND token = 'UBdl6xIwFJjs/6BUjqEryhgQKjjvRxt38pcYO3L/kKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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