SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8776f94b1df3988311d004bcf037ddf0ee6162e8789f5de268038449de40c4fa' 
  AND token = 'TRdDVjnOREHC5jy/WmQieMGnO0d+oUEFZ5lRXUIDiRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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