SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8deb5753ffa89403033078de8a27c22858f371e08abb3794d664fa5f797efa2f' 
  AND token = 'TJBZ+KKMj7PY33/G2hqsAGicAyGUA5VPLSzcObNg/IU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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