SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34cd25c349b20a3037387e34c9bc5c879ee2a28b74f1c4de6ff3984f2317c902' 
  AND token = 'H/+4+hTZYYkUaXjTSb1xyanpDn375QwIhY0kqSmEhnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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