SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deeb777cf70651a21c112ec73c15ddcf11d1e1669bdad4185882c6de784d3c12' 
  AND token = 'YxdHROucyJTnY+kuGV2mOasUUzoBWlS9u5ktkIqhrJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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