SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '676846e6458e93a72e8b3a9d568417d84cb8867070f7e7eb321df7f9d0e4be87' 
  AND token = 'V9Rzgtk7dIStht6KS/QWJdnWhq/Ii9RUO4jyoPj4nNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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