SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd85c628b8ce9bc318cfa495b8fd9d23155f92064ffdd8ba4008f3fb83da9322' 
  AND token = 'i8Q4Kph7A5bgVztEPjnJL0lmAYnzPDnZQxJmzpu6Rco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}