SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfd4e03eef011b5b47b8cc682577e94e3ddcbdda1e99493931db87172b2da039' 
  AND token = 'r7bnadrxa0jGFOpON0bfd/zYMkmVC3E8eKDMBzvWRVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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