SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a065cd8d3de3ad23987cc3b0ee4b958bfdb29184b847fd304e288ee704f8db64' 
  AND token = 'kR5SbYJKlN98dO+A0UQHKbfU16tr39NKU6Pmt3QeFN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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