SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1922d0acc141b14afbb965b843ccdb1cde009b0efefa4dbd8ee904503fd54757' 
  AND token = 'PrnYudHwXD509co/YuT94Z9TRJEf7/B6hdavdXalKRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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