SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35d6deb93e9cb0437d820ec8c183c244cb26d7b795cdf6414680a839f79d028c' 
  AND token = 'KsP8GjdAKB6rVHvMRzkXnS84Uxlq0eTD4Wld1pvHIes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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