SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a3b50ea2dd4cb6d97530d96b84e38611f49642c256cac8d0fdbe0acbb8cec4e' 
  AND token = 'ZrwsGIrEdfKQHgk3uaHG3CYJDdlodAroASKXMAUVsCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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