SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '821ab26c3d0901cf0980094e76a42cbcf1be7dab17514d3583bb80766d4427b4' 
  AND token = 'gT3WYcXJxslKcLF9YPW2CsukUxMiq+34FuqC4LOPYpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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