SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6935375de05a4df049b1772c76e0018883dd945be24ac60ec0ac5301441f3c5' 
  AND token = 'jayy8w6UsqkYUimTJJtyClBTc4828f40fguoKE+FQ6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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