SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccb0c962bfd943ca4c7bb0f93da24909dd8c9aecf605dcd52549140983ec7a3a' 
  AND token = 'UDQXpb7ZppQ+tUBaFGr5oWkhAmu9d5Wb6k8oqlgXLjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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