SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f5912f4313380dd27ddfb960b46ebdf9d1d47767d970c7979e7a94db188188f' 
  AND token = '3XUQ1ls7R83n/enkz4eK+xXo2Ru9yNblk34uQIcVVvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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