SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd0c565af332e115eb7b01c1f663e0a4a9273c548c282bcabb88f688fb6294ccd' 
  AND token = 'ODA69El+2DbTcfa9AHA/fFgPCzIm5YJHjSB45MS3jrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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