SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08cb2deae712623359b783677f47636d10b58ea85723a3cc08bb6b8963cafb26' 
  AND token = 'XImdH8y7AMXAdaQiKKXJLArL7fYViU7r0l5V5WoSMTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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