SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6395ab9366781de514b56e749ee0eb6ccf7afb6a46177fb52efbf48c34691f6d' 
  AND token = '1ImvKnfbPzOnwIyjMSOZCG1JKIyKPDVRUs5bemj81jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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