SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f09db52b69b146c47c6a43f33fb9dd6fd1e0ea93797f8134694b5096de8ba91' 
  AND token = 'GssR0PGAqNAHhd2a3zkaixpsTuEbk6aDvVrhPkcDOJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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