SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72f88d7480870a11354d471558a0b635e4fe368664290964d8f35bf393f856ab' 
  AND token = '3iU/9jM6Gr56cVViCvMmOZitUb70UrxiM1X/Pj2ziUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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