SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bcc125fc90ca7c6a25af252157c42ce671f658bfdf4f7393024846271b55f3c7' 
  AND token = 'rATzPvi8ju4QwmHoaCuTPHT+ojKo5QMkWUdq9G/C8F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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