SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f675d87ba2a538697712a8f4bd2893f7042d74f364638781f2b2ab1b4c71b002' 
  AND token = 'vNBst3tTAKUVbvrqW13mq/6EgSL/FMAeJjK6Ct1WxUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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