SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52154f6c28cb32503aff180073bf080f57fb653d39544efa93bc644cc7b00bdd' 
  AND token = 'PCOjGVBQMAEaOQp5yhEJAF1gVD1WOcvJDwBfXpm0JUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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