SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '743b29033767fe35ceab91a7e537d898effe81b0e896751fe31018863a4cb4ab' 
  AND token = 'nGytrfgFDGgwyciI9xE8sG74Ici5jSE0Z0dlZmyyA4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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