SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9096a1ab9996307aff2a68d20dd854bca02b7cbdc2195f1161d776ee060a3c55' 
  AND token = '+rCvOlTo6v0cC53sEcY9ZjBzBQZqATuXlVGgWwO7sfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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