SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae5085096c83b35fbfa1ebd444f923c5370cec8ef441a0422c4b6037ff7eda17' 
  AND token = 'DZs5OihPvUftjBeZIF8d2+aZtwX/VmKoUV2qS6eMkig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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