SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '67beea8103f8215ff3226567a0b565dce41375debe5f74edcf27747a122a9d7b' 
  AND token = 'Llwxhi9uaitVTTymNb8AuwEX0LWtQp+7i/GEfsgLFl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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