SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6464ec0a5912ae4bfd5fc6560b117b8b9ce292c04ea040517f98b9c62b3883' 
  AND token = 'YIuYunkmiA/w3oWoABdDVw9hYP+KKg+YNUv8mFOvGKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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