SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06923ebc9ccd7225fd76614477e3bf5d4fe3a90e9a94335d782d03f31d735585' 
  AND token = 'muXLbGEoKU+l+HF6YvGwIjJ5AqSwnEG/JYvVhNKhIhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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