SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08135eb43a240d19ee80d90ff667c429cb396a4e985c6a5c347ccbe484fe9459' 
  AND token = 'ICtmlXZ/JQAM9gDQjyLZKMAmdZkqQ8wyu4DtmrLySnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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