SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eae0d7f7c512a9d6916d23c6ddb969bc1f04af017fbf1f97e70463ae265224e' 
  AND token = 'Qu81AeJgn5ukEawhkGty/dtr14SkDnnCBxqIpJRUwvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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