SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '472219f768fde9721efd0f5cd0df8d4b61e3f74c07f4ae421e391356bbd30d67' 
  AND token = '1bAO8/NJWfzo4FL+uioKYJpZ5WyYfDJZgIw8kIjLCHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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