SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ba6cce46e981c26dba74e4d911e3169192e973c7c5adfe33392f238ff9ecedc' 
  AND token = 'jHIKJJl0B6IdSCQrXlBRpVDsBJYdHFRNyg62ionI6nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}