SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ae18a679387455fb87b57fd100c28f1833a2ee277b961125f475f75452fc99e4' 
  AND token = 'HbVAme7o7YcyE9tNQYvQKZtpnhHx95FZOh3JdUjX3EE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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