SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddc1d967f532f72516d5fea1a8f7ff6f3e57232948edccdcadcbcc8496dee82e' 
  AND token = 'Hxz83uMVgvIceK/0fxmQ3FBRjih8D2uVDrgx+/0vX14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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