SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5b68824b6a3513faa5fd06766a0e319dd55f1d232c08d185f6a54b0c9bd4c9b' 
  AND token = 'BI3ragH+O+WlZUOL7kcSjs5DHwuJaTJbzNvMnvQvruM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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