SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67f72cf23096835a10b92132c5c95f9729fce0497c2bbf5214ac491ad3a879f2' 
  AND token = 'zxaH64scyDnWHtX0xExU+4bJ8aQEabLP4nzR/jQHnuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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