SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fd3fcc5d7ab7481a3164411cd542875753c15dd19e07c0be90ecd8a9af9b319' 
  AND token = 'EdMYLL/iOQGgOlt5AoFQ9Qxd0eFut3TfECBRG7d3R2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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