SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '03dd2e6cb07f1344a200a57cc6bd08a3258e8b63053cbe2db00fc5cac8fe0aaa' 
  AND token = 'gypGV6l3eVxnIhYBgNSGr1t+AvxrNCw8CW4w2tJcWjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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