SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d70d7171cf7c6d45ce782df47d33bfcb9e66164bee78e797e3735a814b984ba' 
  AND token = 'COBJ7KWSiK07lKkDfz4U+n5DGi4zGsOQGFta+stORAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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