SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62e5d8bad2f153ca0c80dd3c763731968a34380f46157609b343b3ea5f0ac4af' 
  AND token = 'o4u5Nd9Yb8PdNWTbVJI8Im3RPgk2Ub4Xp+JsyzqlbTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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