SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01600b11f1402bd4399916194d6fe8d06f59806bc836580826f9578f375adb72' 
  AND token = '6wVzOvrBTKq9WGBip66mjxtYkQv5WPo68hqVGYwIZfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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