SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b4c989325b8aac058196f4102ae845d66fbe536f2d4c87e9f122ec85ac2b3c9' 
  AND token = 'Wt4udPuUKJNdIlcnBlCAyqO0GJ7Amjre/QgTyhWyLyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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