SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ccd563ceeee3a8da07fdae212c838db312174081d834361997ec838e3a9edbc' 
  AND token = 'm1B9hcCjClvIdrtB69TsVIqRupuMNZBpgzg5IAyutNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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