SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '617dceca4d6b9e34355ac42d137bcab844c1ccaa8b20aa2cccfec0cc243cb26b' 
  AND token = 'N4ytJUx6vxpSsAsCysNaPKBs1sKITUqFn47UWEPO4MU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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