SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91c0c9cf0192ba7efd9b34a6ca40d585fbe232a89c94e826da076a06a1d53193' 
  AND token = '9OTmWPaWGm4EHqfnhVUl3SOsl/RIUCw56fHAUXEwL6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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