SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a7247bb870d6353f43a286570f9f0a19ef58f9f0a3ce4b54e1adb1ea2827f3c' 
  AND token = 'xfDMozlGWYwqxW1UwlK8ySIFi0KIT5FYNac97Ffdpdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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