SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64fa432aa7d7d1107140ae81324c08e804e699778145b8aef29e641c915d410a' 
  AND token = 'mZqzgXWQZgpno+mBHQSx0EZ29IEg55J8dSr1pTRkkVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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