SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8422841ab28c4c130b3c6c18773f521a61ed0632f6d134765d501c7d7655f735' 
  AND token = 'zS9zDAu4lydQIg9L2GXb8CNZVVPiaAqLaVhQaFnFymU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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