SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f00e8b051df214dc95a3f121285d25ae67257d6c52a30d977665c53d60273b6b' 
  AND token = 'CHbH6KJolajD3RKVComnI03ECXln5FUXnhkqbj79C6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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