SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5937d43665e77aff9d02e85c39897bca6822d7ca131d205ec462ec9742d0d1eb' 
  AND token = '+aaPt2OzjUAsk1B4HImvMm439RVaEKduYcbMQfeTsEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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