SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4edd989a4b9d76ab18895732f65e46a047e37a478bfa6e0c16652bec6f33acd2' 
  AND token = 'Fw9S20mJ9EtwDYJva6trdrpgHjcWDAF/NkYM3qB7i1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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