SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '869c2b585111d0975f179746b85073dbd1a082bea052d20b51089441f7760b64' 
  AND token = 'XIZwR5hv5RwgQpztnkiDic3mCQxdS/v+htnI7vAt6Lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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