SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '885968174d9a50446cfd3c5380b94c56b52e08a1a5b1a85c25f4fe5ed8051f98' 
  AND token = 'Jc9TVtV1Z4D3gzj/ng7CwHvtuHnxVhgiAVMYClZGcok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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