SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b3ba1ad728bd1bc02c0f803c73ca91db49f8d068483372a97a635a7f19330e' 
  AND token = 'FPi31wB5davWV+q8CjVIROuN6IHT1fPpgZrC9lY4LTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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