SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5007a66f174f7055598cf56a9ece76563d531ace8bbcab99fc8bf919e38ed0f7' 
  AND token = 'vnRLAqvB1cYZtyAGGtAmxBHq4S3siIkt/3NJzipgSTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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