SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39b34fc6c55277a086b0a74ee61aadf2c74164b80b457690b588deac29d8f7de' 
  AND token = 'Mg2GZIVx5NVsSB+7q5pwAW/bQQs2qLQNsQoCDDlJ+WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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