SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '946a28cd3122443d65f72d611bc7269b1e9eddfc17580e341053d19e56505351' 
  AND token = 'KoAWLqjWFB8MGOAoLtFfYNpnnTQ9Yitb5pKfA2DefJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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