SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '265af99e2acec7f30a22d35b735207266ef6f602f73ca04804d340ddcc7f0c56' 
  AND token = 'taHqjxqXT4uXQbhL05nVXkkboWo0Ey912XxTJ+YCj7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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