SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eef51b1b7074f09c4cb96cccc35466e74fc8dbfde330d61bb6a7ca90e6e8da27' 
  AND token = 'kW4laZLD53KxzZik1LkhoJMAUXSO/fFMxP2WqvKXysg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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