SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ecd05b57d9071e98cb12290cb3564cc97bba9d9aa64010cfbd8b08d71f5f5c4' 
  AND token = 'mnnLGNGUia2xnl2Q5XI32wtCqqAm/rffnntmfeAZtHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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