SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02b72daf24cfb2860370ea9eca593bba41f6721909056510ef805ca8ccc19a81' 
  AND token = 'QpYbiaDphDcOfyfpfMQn8x8b9IHqM8ma03RvMmNjOug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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