SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c37d9e1620a5e167f820c893f74700ef893781adb0bec9fe8ebbfb50b8c915' 
  AND token = 'We6YSlSD/DQ//mbvOfaCJRvQfd12yNUEbAivdO4wnnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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