SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '26610e504b2d095c48f4d8b8b0bd9aeebc3351797880e30282e1e21660641dc2' 
  AND token = 'RxfDNPpDkfxtfhD1MPcGlGzBFnSsipgzcmwKdkj/wYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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