SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8d1c0c794d95b44d9ab6fc19ad5e7b579a4a9598d4f594e7d0c45e5365ca1c28' 
  AND token = '5FIeiRX9O0JtBnXlUWCPf6uqwRY+VDLixnFCENdKI6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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