SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46621958b2dfef99772b344fccea9925b7fb916adbdbdeb8009acb5a0da00769' 
  AND token = 'k+qMqu5cxEAYq2roRVMRXEGg0m14hzgu5N4lrA3EBaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}