SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '173a7cbd90a7f8d81fd50e3ae3205eb753b89773a6094f54d3f827289c8691cf' 
  AND token = 'IxJBvVN17eJpUEPzorBXQnS3M6dvQ40RVLmITgZZxwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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