SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa0382a3114147c212eb8605bf01d424a8ce9ea4f2a53769f6371271bc8a5a1c' 
  AND token = 'vV8xViulJUgMkFDBWPr8fGuIp86Qja5zhoRYdwglyZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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