SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8579844575230c358230ac6402fb553659e6866ac851e78a6f674290fca9b5f7' 
  AND token = 'CGdRtB0O00bjInG8fhYw4D5ARAZkgsQg88mQQ1LSjuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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