SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb632054c28cd2085bef4f4f5b1422341649acc594119487a2ad662840bbcd2d' 
  AND token = 'sVqoQdMjtS15E4MsxfIUDMS592VyHKgwuzT17DgOtrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}