SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44fe7996e055d8fc5ae79db866789a54bb3c989fb6e282c2c075b9ac8e9e98d6' 
  AND token = 'RE9YD6kCJ4IVnDGlTCDrHJmSCzSQgBzrGFxm+FaVPlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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