SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0773b10325262a1c8e49ed5536768386bb2fa8b9d6d73eb193a8f4a5f1a4b609' 
  AND token = 'QvgDyDCibFU7MFgmSrRl4BkoZ1q4afOGI+PpsI0QvjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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