SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4da228f346554042377d399c7cf8baa3b002bd03374a75fd814c792ef4ba37b3' 
  AND token = 'lny8vNMRGet7t3LtW6gQVrEPd1o8ZXJMsrU7ril3JYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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