SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '008412757e5a33f8bcf9e6f96eb07791bf5e76e9bc987c346f10cdba4ea22dba' 
  AND token = '1agoVfuPmXb3GPtPvisQ13bco9jFJLI1QsCtwSYnIwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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