SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ae5b05bd709dad8cd6b8735c07692f4970e1ffded172789a6643866fbd1061c' 
  AND token = 'zO5LgrPnq1iyPNujh8pjl4QbkDL91AyReJ80XOISBcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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