SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ab273587dbdfcb3512e9b8fa2aac3e6b02e4c580837fc31bfbf3d95147c415d' 
  AND token = 'yHgoAf4MWyKvY7j8wfvBsR0byyxELg0F7EwwgoT8tf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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