SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e279a3b7b69f1a38d45df6a37cdc3ca91c7ae3584bb098df08463b9043fa1e5' 
  AND token = 'BpxN70HlRcnSJjijwUhZQ5jOc1pjo0BG7+b1l9YYUDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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