SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '063a4310d0421cb3cf0a237f68e1afc12378118b179807ac5520856a6396be55' 
  AND token = 'csDx2KhcdLl02DPoW3eVDlTSnh3g7rVftjbugXE5ojA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}