SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9f9eb07da4a3af20d461172d6ed049701f707ba6558bc3a48565fdb2fbfb6d27' 
  AND token = '375vi20c8V/GKKMNTiEKTRrz2i+HJBEkU8JPtJkPrws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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