SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ac4d340a5e8a58a250c184dd5b36a755958250d5618296cb6fdf8531a4090cc' 
  AND token = 'I5WgjbRyVKmuCthwzPcLk+ctW3bKQjNQlV75rYdYsfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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