SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '675a10aa1fca843090ca0cc6cc7d0527193cf0c3fccc71c3f44bad5cda39f5f2' 
  AND token = 'pyO6FJqhLNJluWwauOpgXcuXuLYJKYG7cltpZ8xpJdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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