SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd567accf5ec125a1f4fbffbc578f51359623ad308b84fd1560c3269d743df5' 
  AND token = 'zhrxBNxqNnZb6V5WVDRV7L9X7Jk/jehlku2CmUwA2FU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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