SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f7a9a43bef1836ae73aff4b6b80f9ed601bd2a1998706997b0cf7b2f8ff53cc2' 
  AND token = 'bmX8wAG39bpROQxJbXaJJ/0wQox2wsqTQTOM7qTOpVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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