SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f5bf333aa54911fd034f07a70ef3c578d420c01d024074de88f1bee26ab81893' 
  AND token = 'DI3LeXHu67B6qZfUVZnhGsmRHefmjJfw4+q5RYOeM3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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