SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ebb5cbdda0ae9a699ebcff5a3f942084cd5dacf7077eb880751dd2718f28158' 
  AND token = 'Kkp8/aSm9D/iMUOdsLCD5PT44dtYYiWmnST4ReUKXDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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