SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20b0b9161f1a28f9827e4f16d3e7f4bba20b73a67742319e060565c3b39d5035' 
  AND token = 'qRjZxEn/AqlDaprqBfx9bHi7uuc+TmYvWPSlyDa9W/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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