SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70067b62a9791c32bf085bbb3c0bf6057aa19047f9540488d7299f5318bcd1fb' 
  AND token = '0j20ZG8IABKRqVcuikKJ+fgUBmQ94SvY1hGnZD6bm5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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