SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '334df32090998117bc81f8ed418356dae075e3b1019e29e70f7782746216c9e4' 
  AND token = '9GBQzx9F3JZEQMtNh+AlUDY44BOI6xoDUs4gLVIMXc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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